rel_0_7_04 upgrades to fltk-1.1.3, build support for os x, os x middle mouse...

rel_0_7_04 upgrades to fltk-1.1.3, build support for os x, os x middle mouse button keyboard simulation, os x workaround for partiview/fltk issues with proper redraw. this release is using a recent fltk-1.1.3 cvs upgrade - not the standard release - to resolve OpenGL bugs that will be in fltk-1.1.4. Note that this release of partiview requires fltk-1.1.x support which precludes use of the old file chooser