added error checking
Merge remote-tracking branch 'origin/master'
updates
fixed SafeLiteral()
Merge pull request #19 from manuels/master

Fixed SafeLiteral()
added sider, stitch and clinicaltrials; removed extra ensembl entry
minor
new xref function
removed backslash of single quotes
Merge pull request #21 from dklassen/upstream

removed backslash of single quotes
added url and identifiers.org namespace for wormbase
Merge pull request #22 from JuanCifuentes/master

Add additional detail to wormbase namespace
Merge remote-tracking branch 'upstream/master'