Minor addition to the README.md documentation.

* README.md: added an introductory paragraph and a paragraph on using
the software.
Merge pull request #18 from timothymctim/documentation

Minor addition to the README.md documentation.
Added two missing prerequisites to README.md
Merge pull request #19 from adelapie/master

Added two missing prerequisites to README.md
Skeleton for silvia_manager
Added link for cppUnit (Readme.md)
Added skeleton for src/lib/manager/
Added get_log() method to silvia_manager
Skeleton for lib/manager unit tests
Added entry for compiling the lib/manager unit tests
Cont. skeleton for lib/manager unit tests
Cont. skeleton for manager unit testing
Finished unit test for lib/manager
/lib/manager unit tests renamed
Fixed silvia_manager usage()
lib
Improved lib/manager unit test
simplified hexstring to hex byte array function, cleanup
Fixed comment on get_log_commands() (silvia manager)
Removed src/bin/manager Makefile/Makefile.in from commit