Merge pull request #7 from stuarteberg/master

New patch for vigra: Allow import of RandomForests from read-only hdf5 files.
adds modules for building flask
adds missing sqlalchemy dependency
fixes error in depend notation in jinja2
Add Go language 1.0.3 support.  Add PYTHONPATH variable for buildem
Fix typo in python cmake
Fix golang compilation using obtuse method to get around ExternalProject_Add's horrible string mangling.
cmake script for libpng support in neulib
Add raveler-utils and scons.
Merge branch 'master' of http://github.com/janelia-flyem/buildem
Fix embedded scons reference
ilastik: Added vtk lib dir to LD_LIBRARY_PATH
vigra, ilastik: Clone from specific tags of janelia-flyem github repos.
vigra.cmake: Removed patch commands, which are no longer necessary (fixed in git repo).