ENH:  Set nonzero priors in the mask region even if prior sum is equal to zero.  Also removed unnecessary includes.
ENH:  Set nonzero priors in the mask region even if prior sum is equal to zero.  Also removed unnecessary includes.

git-svn-id: 471e042b35a12bde91bbe895b1188443e6ce8888@365 fd2da0a4-d968-48df-9cb5-d8c496287cbf

vfonov/mincANTS,vfonov/mincANTS,vfonov/mincANTS,vfonov/mincANTS