Add Missing Tooltip for Fill Opacity

Reported by Sean Kennedy. The Fill Opacity setting on Export was missing a tooltip.
Merge remote-tracking branch 'hm-blender/master'

* hm-blender/master:
  Add Missing Tooltip for Fill Opacity
Add Looptools to 'Tools' Tab
Add Print 3D panels to '3D Printing' Tab
Add BSurfaces to 'Tools' tab
Add Cloud Generator to 'Create' tab
Merge remote-tracking branch 'hm-blender/master'

* hm-blender/master:
  Add Cloud Generator to 'Create' tab
  Add BSurfaces to 'Tools' tab
  Add Print 3D panels to '3D Printing' Tab
  Add Looptools to 'Tools' Tab
Fix T38462: error importing PLY with leading space
Clean-up: Updated bl_info['tracker_url'] to developer.blender.org, some minor other edits
Fix error in rBA049a5a86edcf.

Please at least try to start Blender and look at the console after such changes, next time!
Merge remote-tracking branch 'hm-blender/master'

* hm-blender/master:
  Fix error in rBA049a5a86edcf.
  Clean-up: Updated bl_info['tracker_url'] to developer.blender.org, some minor other edits
  Fix T38462: error importing PLY with leading space
Fix strange unicode-related issue from rBA049a5a86edcf...
Merge remote-tracking branch 'hm-blender/master'

* hm-blender/master:
  Fix strange unicode-related issue from rBA049a5a86edcf...