fixes 120. fixes 121. This change prevents a crash in getopt on bad user arguments and prevents the add_annotation function from overrunning the job->metadata array if there is not enough space for the user provided string

git-svn-id: https://svn.mcs.anl.gov/repos/darshan/trunk@808 3b7491f3-a168-0410-bf4b-c445ed680a29