Gmtk

* Minor gmtkViz tweaks to avoid requiring X11 on OS X

* Consistently exit with status 75 on failure due to
memory exhaustion
* Removed some non-portable Bash-isms from shell commands
* "observation" is now allowed as an identifier in GMTKL
(the structure file language)
* Fixed gmtkViz build failure on Ubuntu-derived Linuxes
* Added automatically generated man pages

* Reduced latency in gmtkOnline
* Several bug fixes for writing HDF5 output files
* Added obsfile and obsstream as modules for -verbosity

* Added gmtkMMItrain discriminitive training program
* Added --with-hdf5 configure argument
* EM training warns if Dirichlet prior is responsible for
the entire accumulated count

* Fixed build failure on OS X 10.8 with Apple LLVM 5.1 compiler