1. Fix for active camera export - when cameras bound to markers - option to...

1. Fix for active camera export - when cameras bound to markers - option to export as one camera.    2. poll fix - changed from active object to active camera or selected objects    3. Export of active camera is now optional    4. Export of selected cameras is now optional    5. Naming fix - Changed tracking data export naming for user from BUNDLES to 3D MARKERS    6. Toolbar fix - wrapped in box, options added    7. Code cleanup - Prepared structure for future options of exporting lamps as AE lights, planes as AE solids and object tracking bundles, additional conditions added to avoid AE errors in some rare cases