Check disk stats before throwing on open
Merge pull request #11 from jstalker/file_open_check_fix

Check disk stats before throwing on open
Merge branch 'develop' of /software/vertres/git/origin/vr-pipe into feature/ec2
explicit md5(undef) in remove(); copy() fixed so that it no longer claims to have succeeded when looking at the results of a previous attempt at the same copy that failed due to getting interuppted before the md5 check
made the storage of original_pg_chain optional, so this step can be used anytime on VRPipe-produced bams without filling the metadata with junk
upgraded a warn to a throw so that parsing errors propogate to the sequence_index datasource and prevent invalid dataelement creation
instead of $self->update_stats_from_disc in copy(), we call check_file_existence_on_disc(), just so that a File.t test will pass
version bump
Merge branch 'release/0.142' into develop
Merge branch 'develop' of /software/vertres/git/origin/vr-pipe into feature/ec2