Continued debugging BP1 Writer for a single variable write

Fixed a number of minor things for DataMan engine. The first real-world demo code ran successfully with the AdiosPP framework

Pull request to Jason's branch

Added clang++ for MAC OS in buildDataMan.sh

Added -Wl,-rpath to Makefiles in DataMan examples
Added more variables to buildDataMan.sh

Modified Makefile.libs and Makefiles in ./examples/hello/datamanReader
and ./examples/hello/datamanWriter

Need to set DATAMAN_LOC in those makefiles for local DataMan
installation.

Need to set DATAMAN_LOCATION in buildDataMan.sh for local DataMan
installation.

Run ./buildDataman.sh see contents for detailed info