CMake: Fix libname handling of OpenEXR 2.1. The library built with Autotools was not found.

Weird library names having version suffix (e.g. libIex-2_1.so) are used only
when the OpenEXR was built with CMake.  Building the library with the Autotools
doesn't add the version suffix.
DingTo forgot to make sure kernel_sse41 is compiled in even when empty
Cleanup: some boolean int to real bool.
Fix for rBec81feab6649: better to search for versionned libs first, else it can use your system ones instead of those built by install_deps!
Cycles: Build SSE41 kernel per default, remove build option. This hopefully also fixes some compile errors on various systems.
Fix for icon generation with MSVC

Big thanks to Gaia for getting this working!
OS X linker does not like empty compilation unit by itself in a library. Scons creates one library (.a) per kernel. This fixes that
Added missing include
fixed wrong comment
Cycles: Disable SSE41 kernel on 32bit, we don't use intrinsics here anyway. Also disable it for Visual Studio < 2012, broken blendv instruction.
Fix for minor precision glitch while zooming on clamped view2d
Code Cleanup: avoid duplicate calls to WM_window_pixels_x/y
Rigidbody: Remove keyboard shortcuts to add/remove bodies

We had several reports where users would create rigid bodies by accident
and then wonder why transformations behave differently.
Since these actions aren't used that often, just remove the shortcuts.
Fix build issues with mingw's
Fix uninitialised var warning
Whitespace/Style fix
Code cleanup - Commented out some code which wasn't actually doing anything

gpf->framenum is an int, not a float. Hence, this type of rounding has no effect.
Math Lib: add iroundf function for: (int)floorf(a + 0.5f)
Code Cleanup: float/double promotions
Code Cleanup: use iroundf

also increase precision of rctf print functions