Remove a few unused functions reported by callcatcher

[SmallJoker]

This also removes InvRef::create() shorthand functions which were used only once.
Unused utility functions for Settings or EmergeManager were kept due to potential use in the future

Currently unused functions are...
ChatBuffer::scrollTop()
ChatPrompt::clear()
Client::handleCommand_Deprecated(NetworkPacket*)
ClientInterface::sendToAllCompat(NetworkPacket*, NetworkPacket*, unsigned short)
ClientInterface::state2Name[abi:cxx11](ClientState)
CraftInput::dump[abi:cxx11]() const
CraftOutput::dump[abi:cxx11]() const
DirectionalLight::getViewProjMatrix()
EmergeManager::getContainingChunk(irr::core::vector3d<short>)
EmergeManager::getGroundLevelAtPoint(irr::core::vector2d<short>)
EmergeManager::isRunning()
EmergeThread::cancelPendingItems()
InvRef::createPlayer(lua_State*, RemotePlayer*)
InventoryList::getFreeSlots() const
Map::isNodeUnderground(irr::core::vector3d<short>)
Map::removeEventReceiver(MapEventReceiver*)
MapBlock::getGroundLevel(irr::core::vector2d<short>)
MapBlock::getNodeParent(irr::core::vector3d<short>, bool*)
MapBlock::isValidPositionParent(irr::core::vector3d<short>)
MapNode::serialize(unsigned char*, unsigned char) const
MapgenV6::block_is_underground(unsigned long, irr::core::vector3d<short>)
MapgenV6::getHaveBeach(irr::core::vector2d<short>)
MapgenV6::getMudAmount(irr::core::vector2d<short>)
MeshBufListList::clear()
MeshMakeData::fill(MapBlock*)
NetworkPacket::getU16(unsigned int)
Noise::setOctaves(int)
Noise::setSize(unsigned int, unsigned int, unsigned int)
Noise::setSpreadFactor(irr::core::vector3d<float>)
ObjectProperties::dump[abi:cxx11]()
PlayerMetaRef::checkobject(lua_State*, int)
PointedThing::PointedThing(irr::core::vector3d<short> const&, irr::core::vector3d<short> const&, irr::core::vector3d<short> const&, irr::core::vector3d<float> const&, irr::core::vector3d<short> const&, unsigned short, float)
RenderingEngine::getDisplaySize()
RollbackManager::getEntriesSince[abi:cxx11](long)
SHA1::hexPrinter(unsigned char*, int)
SHA224
SHA224_Final
SHA224_Update
SHA256_Transform
Server::handleCommand_Deprecated(NetworkPacket*)
Settings::getU64NoEx(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned long&) const
Settings::getV2FNoEx(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, irr::core::vector2d<float>&) const
Settings::setV2F(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, irr::core::vector2d<float>)
SettingsHierarchy::getLayer(int) const
ShadowRenderer::mixShadowsQuad()
SmoothTranslatorWrapped::translate(float)
StorageRef::checkobject(lua_State*, int)
TestAreaStore::testSpatialStore()
Thread::bindToProcessor(unsigned int)
Thread::setPriority(int)
check_v2f(lua_State*, int)
con::Connection::PrintInfo(std::basic_ostream<char, std::char_traits<char> >&)
con::ReliablePacketBuffer::print()
createForsythOptimizedMesh(irr::scene::IMesh const*)
fs::RecursiveDeleteContent(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
irr::core::multibyteToWString(irr::core::string<wchar_t, irr::core::irrAllocator<wchar_t> >&, char const*, unsigned int)
irr::core::wStringToMultibyte(irr::core::string<char, irr::core::irrAllocator<char> >&, wchar_t const*, unsigned int)
irr::gui::CGUITTFont::create(irr::IrrlichtDevice*, irr::core::string<char, irr::core::irrAllocator<char> > const&, unsigned int, bool, bool)
irr::gui::CGUITTFont::create(irr::gui::IGUIEnvironment*, irr::core::string<char, irr::core::irrAllocator<char> > const&, unsigned int, bool, bool)
keyname_to_keycode(char const*)
mystrtok_r(char*, char const*, char**)
noise2d_perlin_abs(float, float, int, int, float, bool)
noise3d_perlin(float, float, float, int, int, float, bool)
noise3d_perlin_abs(float, float, float, int, int, float, bool)
porting::detectMSVCBuildDir(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
porting::getCurrentWorkingDir(char*, unsigned long)
push_v2_float_string(lua_State*, irr::core::vector2d<float>)
setMeshColorByNormalXYZ(irr::scene::IMesh*, irr::video::SColor const&, irr::video::SColor const&, irr::video::SColor const&)
srp_set_memory_functions(void* (*)(unsigned long), void* (*)(void*, unsigned long), void (*)(void*))
srp_user_get_session_key(SRPUser*, unsigned long*)
srp_user_get_session_key_length(SRPUser*)
srp_user_get_username(SRPUser*)
srp_user_is_authenticated(SRPUser*)
srp_user_verify_session(SRPUser*, unsigned char const*)
srp_verifier_get_session_key(SRPVerifier*, unsigned long*)
srp_verifier_get_username(SRPVerifier*)
srp_verifier_is_authenticated(SRPVerifier*)
std::deque<ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry, std::allocator<ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry> >::_M_destroy_data_aux(std::_Deque_iterator<ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry, ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry&, ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry*>, std::_Deque_iterator<ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry, ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry&, ServerEnvironment::findSunlight(irr::core::vector3d<short>) const::stack_entry*>)
updateQuicktuneValue(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, QuicktuneVal

To do

This PR is Ready for Review.

How to test

1. Code review
2. Compile

[sfan5]

LGTM + still builds