ENH: Enables specification of PDF Weight for forground and background.

Also removes nonexistant FPR Weight parameter.
Change-Id: I0a18d1bfe96e5895832c76982753d998d7fb0c8f

ENH: Enables popup slider boxes to adjust the object weights.

Change-Id: I41d1f623bc33445d7e296a8c2552f332baced39b
Merge topic 'add-object-pdf-weight-parameter'

56505f4 ENH: Enables specification of PDF Weight for forground and background.
Merge branch 'master' of git://tubetk.org/TubeTK into ITKMetaDocuments

Change-Id: I89aefc02e8ec8ec80280a978fa4c9a01a9e78f74