Create Title subelement via function in TitleInfo.
Remove commented-out line of code
Add name, namePart MODS elements
Add abstract class ModsElementAbstract
Add _mapCreator()

Moved the functionality that maps the DC Creator field into
its own function.
Fix Uppercase letter in name element

Fixed the litteral string used to set the name of the tag
for the name element. Changed it from Name to name.
Add role and roleTerm MODS elements
Add MODS subject element.

For now, only two of the possible sublements for subject are covered:
topic (the default to be used in DC to MODS conversion according to
the MODS website), and geographic.
Add code to handle multiple entries in DC field

Added code to handle multiple entries in the Title, Subject,
and Creator DC fields - the only ones that are coded so far.