Flexible system for sequence labelling display and modification

Jalview's original sequence datamodel assumes that the ID area of an alignment should only display sequence identifiers, rather than other kinds of useful information. This is not always the case, since many IDs are just that - IDs (e.g. GI numbers), and alignment figures typically include informative, human readable sequence labels rather than database entries.

This epic concerns a number of areas. Jalview should allow the user to easily switch naming schemes for an alignment view (and any linked data such as trees, etc). It should also provides ways to perform search and replace functions on ID and other annotation data associated with sequences (e.g. replace particular parts of a sequence ID string with the text associated with a particular type of annotation).