Updated the Prerequisites and installation tips (git added)
Created the translateDictionary and translateList methods in
hierarchyBuilder.py to make the main file (UMLSSubsetBuilder.py) more
readable and to make the code in general more maintainable
Fixed a small typo
Updated UMLSSubsetBuilder.py and hierarchybuilder.py for efficiency by
only translating the relationships dictionary and others when debugMode
is initiated

The program now uses just the cuis, rather than cui-names, throughout
program execution. Rather than translating every dictionary and list
with every excution, as previously, the program now holds off on
translations until the very end. This improves efficiency by preventing
unnecessary querying and datastructure creation from the that used to
occur when not running in the program in debug mode. No changes to the
actual hierarchy structure were made besides a rearrangment of the names
of the entries in the loops dictionary. EFFICIENCY UPDATE.
Removed the unnecessary 'misc' category from the dictionaries during execution