inject error mechanism only when built in at commmand line, to avoid accidental enabling
updating error injection to be invisible when not invoked
better descriptions of the inject error mechanism
minor
Merge pull request #71 from pantheon-systems/inject-errors

Inject errors
fix dav_rename null entry causing assert in stat_cache_value_set
Don't leak file descriptors when LevelDB is failing to write.
Merge branch 'master' of github.com:pantheon-systems/fusedav
Merge pull request #74 from pantheon-systems/rename-coredump

fix dav_rename null entry causing assert in stat_cache_value_set
after merging new changes from master