Simplified CMake file for viewer.
Added raster export to Figure2D class (PNG, JPEG, BMP)
Added SVG export to Figure2D class
Added export current figure action to VIBes main window: Exports the Figure selected in tree view to an image file.
VIBes-viewer: Parsing of "export" action. Filename is given in the "file" string value. File format is deduced from extension. A dialog is shown if file is not specified.
Protected vibes.h header against multiple inclusions
Added saveImage function to VIBes C++ API.
Merge pull request #27 from dvinc/master

Export VIBes figures to common graphics formats (PNG, JPEG, BMP, SVG). Closes #10