COMP: Allow "external" compilation of TractographyLabelMapSeeding

Update CMakeLists.to reference variable also set in SlicerConfig.cmake

This should help to resolve the issue reported on the mailing list:
http://slicer-devel.65872.n3.nabble.com/Building-CLI-outside-of-the-Slicer-Build-tree-tt4031199.html

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23002 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Enable numeric sorting in LabelStatistics table

Data is added as float in a QtVariant with Qt::DisplayRole, in stead of text. The
enable the columns to be numerically sorted.

From: Bradley Lowekamp <blowekamp@mail.nih.gov>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23003 3bd1e089-480b-0410-8dfb-8563597acbee
BUG: Fix documentation targets

Move 'doc' target to be created, initially with no dependencies, to the
root CMakeLists.txt, so that it is always available for non-Doxygen doc
targets (e.g. SlicerWizard-doc). Change doxygen doc target to be a
separate target that is then added as a dependency of 'doc' in the same
manner as SlicerWizard-doc. Remove logic to control when targets are
part of the default target except from the root 'doc' target (since
duplicating it is superfluous).

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23004 3bd1e089-480b-0410-8dfb-8563597acbee