(LtcReader) Fix timecode type

Prior to this commit, the LTC decoder converts the timecode to a frame
number with a hardcoded 25 fps timecode type. PhLTCReader clock is
indeed set to 25 fps at creation, however it is changed to the video
fps in Synchronizer::onVideoTCTypeChanged. With a 24 fps video, the
LTC decoder would slowly drift.

To handle this situation, use the clock timecode type instead of
hardcoding it at 25 fps.
(LTC reader) Use ltc.h function to convert LTC frame to timecode

The current code is right, but libltc already provides a function
to achieve that which a little clearer. Using this function also
allows to rely less on libltc internal timecode representation.
OpenGL textures double-buffering

Repeatedly uploading to a texture and displaying it can cause the
CPU to wait for the GPU, slowing down the application. A classic
technique to make the transfer asynchronous is to use double-buffering:
Two textures are used, the GPU draws one of them and the CPU uploads
to the other one.

See 'Double Buffering Texture Data' on the following page:
https://developer.apple.com/library/mac/documentation/graphicsimaging/conceptual/opengl-macprogguide/opengl_texturedata/opengl_texturedata.html
Merge pull request #213 from tlecomte/tlLTCframe_to_time

Small cleanup in LTC reader : use libltc function to convert LTC frame to timecode
Merge pull request #212 from tlecomte/tlLTCTimecodeFix

Fix LTC decoder timecode conversion
Merge pull request #215 from tlecomte/tlTextureDoubleBuffering

OpenGL textures double-buffering
add apple documentation link + uncrustify
uncrustify
Update README with more Windows steps
Enable bilinear filtering for nicer video scaling.

Prior to this commit, the video is scaled with a nearest-neighbour
filter. This produces 'blocky' images on screen. By switching to
bilinear filtering (which is standard), much nicer images are produced.

The change to bilinear scaling implies an additional modification to
specify how the filter handles the pixels at the edge of the video.
The scaling by default uses a `repeat' mode, which is only
appropriate when drawing a repeating pattern. So we use `clamp to
edge' as appropriate here for all textures apart from the strip
background.
Merge pull request #217 from tlecomte/tlWindowsReadme

Update README with more Windows steps
Add more settings for GraphicTest
Better font handling
Merge pull request #218 from tlecomte/tlTextureBilinear

Nicer video scaling with bilinear filtering
Tweak video pixel format for faster OpenGL texture loading

Instead of sending a RGB buffer to the card, send a BGRA buffer.
The 32-bits alignment and the blue/red order are likely to be
native to the video card, avoiding costful conversions.

This combination is reported to best here:
http://www.opengl.org/wiki/Common_Mistakes#Image_precision
https://developer.apple.com/library/mac/documentation/graphicsimaging/conceptual/opengl-macprogguide/opengl_texturedata/opengl_texturedata.html#//apple_ref/doc/uid/TP40001987-CH407-SW1

On a Windows 7 PC with Intel HD Graphics card, timing the
glTexSubImage2d calls produces the following results:

-before the commit: Mean = 9.4 ms, standard dev = 1.5 ms
-after the commit:  Mean = 5.4 ms, standard dev = 1.6 ms
Merge pull request #219 from tlecomte/tlOpenGLTextureFormat2

Tweak video pixel format for faster OpenGL texture loading
uncrustify