(Re-)adding pluginEditor icons, Fixing problems with more than one plugin in the editor, other bugfixes and (it at least seems like to) fix an issue with loading the plugins..
Merge branch 'pluginsystem' of github.com:fodinabor/Polycode into pluginsystem

Conflicts:
	Core/Contents/Include/PolyEntity.h
	Core/Contents/Include/PolyPlugin.h
	Core/Contents/Source/PolyPlugin.cpp
	IDE/Contents/Source/PolycodeEntityEditor.cpp
	IDE/Contents/Source/PolycodePluginEditor.cpp
	IDE/Contents/Source/PolycodeProps.cpp