WinRT: removed a completed TODO item from an inline comment

WinRT: added initial SDL_TEXTINPUT support Further support regarding IME and on-screen keyboards is pending, some of which might not be 100% compatible with other platforms, given WinRT platform restrictions. An MSDN article at http://msdn.microsoft.com/en-us/library/windows/apps/hh465404.aspx indicates that on-screen keyboard display requires that the user first tap on a Windows/XAML text control. This change adds basic SDL_TEXTINPUT support, with input coming from hardware keyboards, at a minimum, and without the need for XAML integration (which is still pending integration into SDL, by and large).

Corrected header file guard comments.

Fixed limitation for number of custom main() arguments on Android. Limitation was size of the reference table because local refs were not deleted.

Mac: Add drag & drop support. Fixes bug https://bugzilla.libsdl.org/show_bug.cgi?id=2757 Thanks to Alex Szpakowski for the patch!

Cocoa: add in handling of "lost" touches on OS X. [bug #2635] This scenario can occur, for example, when the 4-finger touch sequence is used to switch spaces. the SDL window does not receive the touch up events and ends up thinking there are far more fingers on the pad than there are. So the solution here is everytime a new "touch" appears we can through and check if there are any existing known touches by the OS and if there are none, abut SDL things there are, we simply go through and cancel the SDL touches. Side affects. - the "touch up" won't occur until the users sends a new touch (could be well after the actual release really did occur)

add "i" shortcut to testgesture tool to log # of fingers down on the touch devices.

add controllermap program to SDLTest xcode project

Fixed doxygen tags in header file documentation comments.

Fixed typos in header file documentation comments.