#14 Support duplicate section names

[Greg Chabala]

I considered using ini4j to parse QuickFIX ini files, but unfortunately these have duplicate section names. See an example here:
http://www.quickfixj.org/quickfixj/usermanual/1.5.0/usage/configuration.html#Sample%20Settings%20File

ini4J 0.5.2 currently is unioning duplicate section names, and if keys within duplicate sections are equal, the last value wins. As duplicate sections are somewhat non-standard, I request that there be configurable behavior to parse duplicate sections and keep them distinct, such that they may then be retrieved as a list with the getAll() method.