adding undo support to curation modules
moved curation modules to meting ear source tree
made a distinction between the abstract and interval ChemicalIdentifier classes
improved the peptide generated by the peptide factory. the coordinates are now set for all atoms and every other residue is reflected on the plane of the peptide chain.
Default description for author annotation is now clearer
Corrected description of cross-reference
added Task - a label interface so we can indicate the annotations specific to tasks
corrected sorting of supported identifiers - we should always sort by their description.
removed PubChem as a synonym for PubChem-Compound but added `CID`. Users also refer to PubChem-Substance using simply `PubChem` and thus this synonym is ambiguous
default editor for annotations which can't be edited is now more descriptive
added sorted order of annotations