Merge pull request #3 from agtorre/2.4dev

changed parse so that it kills plfs on an invalid key and fixed some com...
Added warning for nonexistant PLFSRC file, check existence of files
before trying to load them to allow fall-through
Updated failure path
Updated types
Fixed build on older cmake (2.6 patch 4)
Moved /yaml-cpp into src/Plfsrc/yaml-cpp