Gazebo OPC UA integration

Currently supports creating manipulator/positon/velocity objects and simple set/read of values over OPC UA. Server is notified when updating one of the values. WIP: PubSub integration.

Was built for Ubuntu 18.04, Gazebo 9, OPC UA bundle v1.7.4. Might work with other envs.

1. Download C++ based OPC UA Client/Server SDK from HERE (you need login at first)
2. Extract and set export UASDK_BASE_DIR=PATH_TO_DOWNLOADED_SDK/sdk/, better to add it in bashrc file

1. Go to the root of the project
2. To find the plugin: export GAZEBO_PLUGIN_PATH=${GAZEBO_PLUGIN_PATH}:./build
3. To find model files: export GAZEBO_MODEL_PATH=${GAZEBO_MODEL_PATH}:./models
4. gazebo iiwa14.world Or better (paused and verbose): gazebo -u iiwa14.world --verbose

The simplest way to change value - download UA Expert
Run gazebo at first and UaExpert will find connection automatically.

Changes to values can be caught in the intern_nodemanagerinternship.cpp in the method 'beforeSetAttributeValue'

Build with debug flag because of license cd build && cmake .. -DCMAKE_BUILD_TYPE=Debug && make && cd ..

To repeat the same from scratch you need to create a tree of types in the UaModeler and generate code for objects