Reverted OS X implementation to non-ARC

 * Apparently, there were some leaks not reported as such
 * Support for 32 bits computer is restored
 * Fix memory leak in sfStringToNSString (related to #484)
 * Unapply context when closing the window, freeing memory

The following commits are related to ARC modifications:

 * 42f6e83dfbd73d8819287caddb250afd697729ba
 * 6edc4b951838771340512f7b91b27f05039ae606
 * f6c94451fb9262f52f537a4c5fff2309c2a89076
 * 324d4a18e716070582fc8e659387f9b72a3d42a3
 * 0d470561326bac4e8985bdbd5e139c9e3a276566

Commit ac28902b57094518e40b138b691b91f0f8004604 is the last one before the introduction of ARC.
Replaced deprecated functions on OS X 10.9
Fixed warnings in Cocoa example
Improved style of Cocoa example
Removed unnecessary check in cmake regarding the deployment target

 * Setting CMAKE_OSX_DEPLOYMENT_TARGET to something implies setting CMAKE_OSX_SYSROOT too
 * The default values are enough for most users
 * If someone is trying to compile SFML with 10.6 SDK it will simply fail later anyway
Renamed INSTALL_XCODE4_TEMPLATES to INSTALL_XCODE_TEMPLATES

Templates are compatible with versions 4 and 5 of Xcode.
Added config of Xcode templates according to CMAKE_OSX_ARCHITECTURES
Improved CMake script

 * Instead of configuring Xcode templates directly to /Library the files are first saved in CMAKE_CURRENT_BINARY_DIR
 * This avoid running CMake as root on some systems
Removed old documentation that doesn't apply anymore
Moved more responsibilities to SFOpenGLView

These changes will ease the implementation of mouse grab (#394)