setting init() to non pure virtual and removing useless implementation

like in PhGraphicLoop
The new way SHOULD work but fail (see description)

Due to bad implementation of colors in OpenGl and alpha filter.
job's almost done, steel some issues with letter spacing
Last commit
text is rendered with transparency
rename variable in PhGraphicText::draw
remove unused PhFont members
better error handling for PhFont
PhFont ++
drawing the text over a rect
fix font height
linear min/max filter for texture rendering
font size set in PhFont
GraphicStripTest uses Swenson as default font
GraphicTest can change font
new PhFont::setFontFile method
GraphicTest handles font load error
new PhFont::select method + doxygen
GraphicStripTest use new PhFont system
Merge branch 'master' into mdGraphicStrip2

* master: (24 commits)
  fix bug on the left of the strip after resizing
  remove red background
  Joker handle new video engine and strip
  fix video freeze
  free AVPacket
  video playback optimisation
  adding the de-activation for console output on PHDEBUG (see
description)
  VideoTest can open another file
  adding reverse play to VideoTest
  fix default color to white for PhGraphicObject
  better layout
  better y handling for strip
  first working strip + videoEngine
  PhGraphicStrip doesn't use view anymore
  cleaning unused video engine: qtvideo, vlc, qtav, ffmpeg with widget
  new VideoEngine
  fix include <> ""
  remove old file from VideoStripTest.pro
  stop PhGraphicView timer in destructor
  fluid video stream with opengl scaling
  ...

Conflicts:
	libs/PhGraphicStrip/PhGraphicStrip.cpp
	libs/PhGraphicStrip/PhGraphicStrip.h
	tests/GraphicStripTest/MainWindow.cpp