Use Object.Instantiate to copy Skin. Util function is suspect, and is…

… copying the whole GUIStyles too, unnecessarily in this case.

Save and restore GUISkin around GUI operation (because other GUI might not set anything, eg. dev console).

Go back to having HSTRETCH default to true for Label.

Merge branch 'master' of https://github.com/KSP-KOS/KOS into gui

Add TabWidget tutorial to doc.

Add "VISIBLE" for reading HIDE/SHOW state.
Tweak radiobuttons to work reliably over comm delay.

Move style attributes to a class of their own.

Add SKIN to GUI allowing single-point-of-change in styles,
and changing of sub-part styles.

Merge branch 'develop' of https://github.com/KSP-KOS/KOS into gui

Fix Button:PRESSED breakage in alpha4.

Add connectivity and signal delay support to GUI.

Add "CHANGED" attribute to PopupMenu (like TextField).
Make it easy to use objects other than strings in a PopupMenu.

Add RADIOBUTTON, SCROLLBOX and POPUPMENU widgets.

Revert scope-based widget deletion.
Add explicit widget disposal (removal from parent).
Make top-level window auto-resize.
Fix blank transparent space window margins.

Split MARGIN into HMARGIN and VMARGIN

Split PADDING into HPADDING and VPADDING
Add ADDHLAYOUT and ADDVLAYOUT - like HBOX/VBOX, but default to entirely no style or borders, just pure layout.Honour scoping so that UIs can be usefully made with locals, not just globals.
Optimize styles to avoid creating new ones until actually changed.
Make LABEL and SLIDER honour HSTRETCH being set to false (and it will now default to false too on LABEL)
Tweak initial hslider style.