Removed deprecated .nonBlocking flag from session configuration since connection is always configured for non-blocking and async operations are specified on each operation via presence of a closure/callback
Tweaked logging to log interupted socket operations only at level 3
Reduced logging level for system throughput tests
Makefile consolidation: use pattern rules when possible, tag PHONY targets.

Also, don't make 'all' target depend on 'clean', add TAGS target.
Include socket99 include directory in LIB_INCS.

I missed this because socket99.h is in my /usr/local/include/, which was
getting pulled in automatically.
Fixed concurrency issue in examples and system tests relating to overlapped/async PUT operations
Merge branch 'develop' of github.com:Seagate/kinetic-c into develop
Updated README to note the presence of the various types of I/O operation mechanisms.
Trying to fix links to source folders in README
Fixed path issues in README