Merge pull request #1 from clbr/build

Linux build support + a warning note
small error handling issue
toolbar skeleton
toolbox skeleton
toolbox and screen size handling
reallocate without input parameter
Some button event handling.
Track to contain preparing Track stuff - basic interface, first few function
Toolbar button identifiers are now public
basic camera
-1 camera icon
Clicking on free camera button now works
enum fix for gcc
Class hierarchy for removable operations
class for track's objects
unnecessary local variables were removed
object moving and rotating
undo/redo buttons
object selection - not stable
Entity class removed, its existence was unnecessary