Blur plugin take's into account the project's color model

[felixadandenault]

This modification of the blur plugin alows for the plugin to take into account the colour model of the project. The plugin gui includes three new check boxes (Y, U, V,) and two dials to adjust the combination of Y to RGB and UV to RGB, when both a RGB and a YUV components are checked.

All modifications, except modification in the same color space, as the project, require some lossy conversion from RGB to YUV and YUV to RGB.

[felixadandenault]

blur.C, blur.h, blurwindow.h, blurwindow.C