Lots of fixes and optimizations:

- divided both projects` debug and release branches

- fixed a small bug in the config reader

- got rid of BGRA in GIF decoder

- made alpha blending more comprehensible

- optimized the semaphore code on Linux

- modified the cursor (also on Linux), now it`s a pointing hand like on Win32

- changed the way mouse coords are obtained (Linux)

- added the missing <dirent.h> include (Linux)