Cleanup.

Removed unneeded files.
futils - removed tabs.

sed -i 's/	/    /g'  semaphore.h timer.h
Added betweenness function.
Added make_dag function.

 - moved make_dag out of betweennes function.
 - updated test.
betweennes code cleanup.

 - removed nested structures.
 - iterative version of counting.
 - updated test.
 - added comments.
Merge branch 'mmd'

Conflicts:
	std/demo/cache/Makefile
	std/demo/cache/README.md
	std/demo/cache/db_cache.cpp
	std/demo/cache/db_cache.h
	std/demo/cache/mysql_client.cpp
	std/demo/cache/mysql_client.h
	std/demo/cache/test.cpp