Revamp light falloff calculation in Encoder

* Remove Linear, Quadratic and Constant calculation from Light class
* Perform exact calculation of range rather than using approximation algorithm
* Remove falloffExponent as it was unused
* Default range parameter to 1.0f directly, rather than deferring until actually writing to .gpb
Add conditionals in default shaders for using medium precision

Some devices have problems with high precision floats. I have tested
Nexus 4 and Nexus 7 with Android 4.4 having lightning artifacts when
using highp floats but work fine with mediump.
Fixed Sample browser build on Android
Merge pull request #1364 from rgngl/sampleAndroidFix

Fixed Sample browser build on Android
Merge pull request #1362 from rgngl/mediumpShaders

Add conditionals in default shaders for using medium precision
Merge pull request #1361 from staticfloat/encoderfix

Revamp light falloff calculation in Encoder
Fixed luagen build on OS X
Merge pull request #1367 from rgngl/luagenOSXfix

Fixed luagen build on OS X
Merge branch 'next' of git://github.com/blackberry/GamePlay into helpful-additions-textureCube
Moved cubemap shaders from res/common/shaders to res/shaders (a local one to the browser sample)
Rewrote cubeenv.material and TextureCubeSample.cpp so that it would render properly
Fixed not finding Arial font.
Made sure __currentTextureId was set to a default value.
Some syntax changes (not sure if proper, but otherwise seemed like mixed usage of spaces between parenthesis for macros GP_ASSERT and GL_ASSERT)
Made sure any glBindTexture that wasn't Texture::Sampler::bind would revert back to the "current" bound texture at the time.
Made sure Texture::Sampler::bind would only bind the texture if it wasn't already bound.
Added ability to specify what format the FrameBuffer screenshot should be in (RGB or RGBA)
Updated Lua bindings for FrameBuffer (and seems Properties wasn't updated either)
Reversed view direction in cube map shader.
Fixed texture cube sample (camera is in degrees, not radians)
Changed encoder and luagen projects to use Visual Studio 2013