reads terms from a .txt version of the XML format for terms, and returns a Python dictionary. The keys are always the term names, but the user may specify whether the values are the terms' description, hierarchy path, type, domain, or short name. It is also possible to specify that all term information be included in the value field.
The format of the XML file read by readTerms() is pasted from an e-mail from Dave.
NOTE: I've added extra tags for the FGDC-specific fields of type, domain and short name.