Allow type codes I for inactive and U for unassigned.
Add hash verified cacheing of fiber maps.
Deepcopy takes too long
Add .plate caching.
refactor .keep_all -> .mustkeep
Add support for assign_to = [rb], keep track of mustkeep in file key/value pairs, better constraint handling and violation checking in assign.py. add a max_priority function to field.py to get the maximum priority of the targets
Make targets link to their setup. This is ok since get_plate does not return a singleton instance of the field.
Enhance graphcollide to support undroppable targets and remove (unused) default weighting based on node order. Use enhancements in assign.py
Speedboost
Get assign_with fully working, adding keepall option to .setup to not drop targets when assigning multiple setups together.
Fix drawing of duplicate holes.
Add new filters
Allow lower case type codes
Add function to return all colliding nodes.
Improve/tweak UI.
Some code tidying
Allow < MIN_GUIDES if user supplies fewer.
Slightly decrease plate radius
Parameterize conflict radii, add support for maxsky, and support minsky at the plate planning stage.
Good to go for December 2014 Development. This baseline for Dec2014 branch.

Merge branch 'Sept2014' into develop

* Sept2014:
  Parameterize conflict radii, add support for maxsky, and support minsky at the plate planning stage.
  Slightly decrease plate radius
  Improve/tweak UI. Some code tidying Allow < MIN_GUIDES if user supplies fewer.
  Add function to return all colliding nodes.
  Allow lower case type codes
  Add new filters
  Fix drawing of duplicate holes.
  Get assign_with fully working, adding keepall option to .setup to not drop targets when assigning multiple setups together.
  Speedboost
  Enhance graphcollide to support undroppable targets and remove (unused) default weighting based on node order. Use enhancements in assign.py
  Make targets link to their setup. This is ok since get_plate does not return a singleton instance of the field.
  Add support for assign_to = [rb], keep track of mustkeep in file key/value pairs, better constraint handling and violation checking in assign.py. add a max_priority function to field.py to get the maximum priority of the targets
  refactor .keep_all -> .mustkeep
  Add .plate caching.
  Deepcopy takes too long
  Add hash verified cacheing of fiber maps.
  Allow type codes I for inactive and U for unassigned.