Project: removed THIS_IS_THE_ENGINE compiler flag

This flag is obsolete for a while already
Project: removed built-in plugins from the Windows build
Common: fixed AllegroBitmap::RotateBlt()
Switch Allegro driver to GFX_XWINDOWS* family for Linux
Compatibility: Characters can always walk through each other on < 2.54. This fixes the partner character not walking into the old man's apartment in Pleurghburg.
Merge pull request #57 from s--d/linux-fixes

Switch Allegro driver to GFX_XWINDOWS* family for Linux
Engine: Permit Allegro auto-detect ("magic") driver for Linux at compile-time only.
Merge pull request #58 from s--d/linux-fixes

Engine: Permit Allegro auto-detect ("magic") driver for Linux at compile...
Common: fixed String memory management
Linux README: Update version number in commands.
Windows: Added ALLEGRO_NO_ASM compile flag for Debug build
Consistent version in Engine and Editor: 3.30.0.1130
Fixed mistake in version representation.

Final version number: 3.3.0.1130.
Engine: fixed exception message

Exception in exception handler... irony of that.
Updated Copyright.txt

Added few more contributor names, sorted in alphabetic order.
AGS.Native: fixed using uninitialized AssetLibInfo object
Merge branch 'master' into develop
Updated version 3.3 new features in welcome pane
Makefile: removed PIE and FPIE compile flags for Linux
Engine: corrected Theora playing callback