Simply Makefile a bit.

Explicitly list dirs with source files instead using file.
Use VPATH to find source files.
Eliminate need to generate rule for each .o dependency.
Stub out bfd monitor client library.

Getting the build setup to compile the monitor client library and a test
application that links to the lib to exercise it.
Rename bfdmon -> bfdmonClient.

Make the client library files obvious that they are not used in the server.
Start fleshing out monitor client lib and test app.

Added parsing of a session file to bfdmontest.
  - Added bfdmontest.cfg to exercise parsing.
Added connection to monitor server via client lib.
Added application agnostic logging to client lib.