Fix plfs.spec file and some compile errors for the unittest tool

Remove the YAML library files, now they will be included in the
PLFS library directly.

Fix the mis-match types between the unittest tool and small file
and some compiler warnings.
Merge pull request #280 from thewacokid/master

Fixed compiler warning/error w/ gcc 4.3.4.  Also fixed compiler warning/error with APPLE...
Merge pull request #282 from thewacokid/master

Fixed comparison of pointer/NULL with < 0.  gcc 4.7.2 found this.
Merge pull request #279 from zhang-jingwang/master

Fix plfs.spec file and some compile errors for the unittest tool