[Mihail Naydenov]

Supplied here is:
- Callbacks implementation;
- Full implemetation of callbacks for FIF_TIFF, FIF_JPEG Loading and FreeImage_Rotate utility function.
- Helper class (wraps the callback struct) for easy adding callbacks to any loading or utility function inside FreeImage.

Callbacks support + simple test

For more detailed info:
https://sourceforge.net/projects/freeimage/forums/forum/36111/topic/4004822

Forgot to mention the Rotate function also has improved performance because the use of AssignPixel instead of memcpy and for loops.

The gain is considerable mainly for big, higher depth images (up to 40%).

Adds TARGA support, Save to JPEG, TIFF, modules enum

Added modules enumeration. (In future it can, together with callbacks, be used for better error report)

Added Load and Save callback to TGA, Save callback for JPEG and TIFF.
(As it is evident form the code, it is extremely easy thing to do.)

For now I put development on hold, until some feedback is given.

A quick note:
CallbackHelper::reportStepProgress()

should check for _cb first, not after the % check, otherwise if _gran == 0 it will crash.

Another quick note after using the patch for a while.

The loading functions is probably better to return NULL instead of partially loaded dib. There is nothing wrong in current impl, and is a bit easier, but in the real world it is hard to track if the dib returned is a result of loading or cancellation.
It is not impossible to workaround this, but, considering the dib will be discarded in 99.99% of the cases, it is better and simpler to just return null (we need to unload first of course).

Add patch, implementing the last two comments issues.

All previous + fixed issues from comments

fix dib=NULL return; for rle cancel