created a branch openmp and updated cmake with OpenMP flags
Major Updates
kdtree building reimplemented
Files updated
Merge branch 'updated' into openmp

Conflicts:
	fof_cluster_finder/CMakeLists.txt
Minor updates
resolved merge conflict
added unit test stuff to openmp branch
removed unwanted ~ file
Bug fix in fileio_class
Option updates and bug fix
Minor update
Documentation Update
Fileio update
Minor updates
fixed unit test so that it runs by 'make test'
CMakeLists.txt modified so that test is enabled from the cmake root
Updated comments for class: astro
fof_class.cpp minor update
Updated comments for class: cluster_class