Add name conversion feature to post-install scripts.

Implements issue #81. Post-install scripts can now execute a `convertName()`
method that will convert a string from one naming convention to another. For
example,

    convertName("test-string", from: HYPHENATED, to: "PROPERTY")

will convert a string from lower-case hyphenated form to property style. You
can find all the supported name forms in the new `NameType` class.