Added type-safety helpers to ObjectEntry
Fixed small naming issue.
Added more safety checks to config loading for PolycodeProject
Removed Entity::qPitch/Yaw/Roll

These were protected, and grep revealed they were not used anywhere.
Converted Entity::tags to a pointer.

The idea is that most entities don't use tags, so wasting space on it when it's not needed isn't a good idea. tags is protected, so this does not affect the public API. All the functions that use tags were updated appropriately.
Merge pull request #265 from CIB/less-memory

Entity memory optimizations
Merge pull request #259 from CIB/cleanup

Type-safety helpers for ObjectEntry
Merge pull request #258 from CIB/documentation

Documentation stuff
Added a shader clearing call in ScreenMesh rendering, fixed zlib URL
Added an instance of the Logger to CoreServices and added a nonstatic log method called logBroadcast that dispatches a notify event from the Logger instance so that they can be printed to listening consoles. Made the GLSL module use the log broadcast for its error message. Made IDE console listen to Logger broadcasts.
Added doxygen comments to ScreenEntity
Added doxygen comments to UIElement