v2.50pre2 released !

v2.50pre2 : 4th of April 2006
- set_rle_mask => set_mask
- Modified CamROIIntersect function so that it doesn't return a CamROI (pb. incompatibility C/C++)
- Added management of CamImage masks (not just CamRLEImage as before)
- Added implementation of separable linear filters
- Added CamRefCopy function
- Added CamFixedFilter function and an implementation of 3x3 to 7x7 gaussian filtering