[opengl] WGL_render_texture / WGL_ATI_pixel_format_float

[Raphael]

Hi,

Anyone Can test this demo 
http://www.paulsprojects.net/opengl/rtotex/rtotex.html
If have an ATI card who support WGL_ATI_pixel_format_float  ?

Thx

Changelog:
 - support WGL_ATI_pixel_format_float / WGL_ARB_color_buffer_float
 - implement WGL_render_texture using GLX_ATI_render_texture (when available)
 - better WGL_render_texture emulation (using PBuffers)
 - fix wglMakeCurrent (and add usefull traces)

Regards,
Raphael