cellPngDec Module Added

Implemented 'cellPngDec', using 'sys_fs' to access the files and the
'lodepng' library to decode PNG buffers to Raw-pixel buffers that can be
used as textures.
cellJpgDec Module Added

*Replaced "sys_jpgdec" with "cellJpgDec" in
"rpcs3\Emu\SysCalls\Modules.cpp".
*Implemented 'cellJpgDec', using 'sys_fs' to access the files and the
'jpg-compressor' (jpgd) library to decode JPG buffers to Raw-pixel
buffers that can be
used as textures.
*Fixed memory leak issue in cellPngDec and minor changes.
cellGifDec Module Added

*Implemented 'cellGifDec', using 'sys_fs' to access the files and the
'stb_image' (stblib) library to decode GIF buffers to Raw-pixel buffers
that can be used as textures.

*Replace 'lodepng' and 'jpeg-compressor' libraries with 'stb_image' in
cellPngDec and cellJpgDec, respectively.

*Fixed minor issues in cellPngDec and cellJpgDec.
Keybord support Added

* Implemented 'cellKb*' functions from 'sys_io' module, which are part
of the libkb library.

* Added corresponding entries in the 'Config > Settings' menu to change
the handler of the keyboard. Supported handlers: Windows, Null.

INFO: This keyboard library is *very* experimental and I am aware of
some bugs. There will be improvements soon.
Keybord support improved

*Improved Keyboard:
- Fixed crash when using Null keyboard handler
- Added support for meta keys
- Added support for {caps, num, scroll} lock.

*Small issues fixed in previous module:
- cellGifDec: Fixed wrong information of packet field in
cellGifDecReadHeader.
- cellGifDec: Set DataOutInfo.recordType as 1 since the output is always
an image.
- cellJpgDec: Set colorSpace as 3, until a better function is
implemented.
- cellJpgDec, cellPngDec: Added RGBA support.

*Changed layout of "Config > Settings" menu.
Mouse support added

*Implemented 'cellMouse*' functions from 'sys_io' module, which are part
of the libmouse library.

* Added corresponding entries in the 'Config > Settings' menu to change
the handler of the mouse. Supported handlers: Windows, Null.

* cellGifDec: Fixed some errors and added support for RGBA color.

(Remember: The mouse support is very experimental)
Minor issues fixed

*Memory leak in image decodification modules.

*Changed mouse wheel delta value.
Merge pull request #4 from AlexAltea/master

New image decodification modules & IO devices