initial setup for doxygen on bencho submodule has been added
finished doxygen setup

* modified Bencho submodule
* added target 'docs' to Makefile that calls target 'docs' of ./bencho/Makefile
modified submodule bencho
Added some documentations to bencho submodule
Updated bencho documentation
updated bencho submodule
resolving merge conflicts while merging branch feature_doxygen into master
updated bencho submodule