Implemented a more flexible blending system (fixes #298)
Created branch for experimental blending mode API

See issue #298.
Based on branch 'new_blending_api' of github.com:tomgalvin594/SFML.
Adjust CMake module to provide correct deps on OSX

Module will now give the OpenGL framework as a dependency instead of the
nonexistent libGL.
Fixed compile error (trailing enum comma) and other minor things
Omitted "Blend" prefix for nested BlendMode enums

BlendMode::Factor instead of BlendMode::BlendFactor
BlendMode::Equation instead of BlendMode::BlendEquation
Improved formatting
Improved documentation
Passed BlendMode objects by const-reference
Fixed various linux compile errors in EglContext
Merge pull request #574 from jcowgill/egl-linux-fixes

Fixed various linux compile errors in EglContext
Improved fullscreen support on OS X (close #343)

No hard resolution switch is done. Instead a view of the requested
size is displayed in the center of the main screen (letter boxing).

Running a stress test showed that the performance were equal
to a hard switch without the inconvenience of resizing the
user's apps. This also follows the guidelines defined by Apple:

> Avoid changing the display resolution from that chosen by the user.

source:
https://developer.apple.com/library/mac/documentation/graphicsimaging/Conceptual/OpenGL-MacProgGuide/opengl_fullscreen/opengl_cgl.html
Add support for retina displays (close #353)

Based on PR #388 by Michael Bradshaw

Convert size to match the size requested by the user.
Replaced some deprecated functions on OS X

NSWindow convertBaseToScreen: -> convertRectToScreen:
NSView   convertPointToBase:  -> convertPointToBacking:
Fixed mouse tracking in fullscreen on OS X
Removed debug log forgotten in the previous commit
Removed dead code

AutoreleasePoolWrapper is no more used since ARC is used on Mac.
Fixed menu shortcut not working in fullscreen (close #537)
Reviewed the sf::BlendMode class (added a constructor, made minor modifications in comments)
Fix text being rendered with a vertical offset when the font's ascent doesn't match it's size.
Merge pull request #576 from binary1248/text_fix

Fix text being rendered with a vertical offset when the font's ascent doesn't match it's size.