Tidy ParseUtils

This MR tidies the ParseUtils class and removes a number of inconsistencies in function naming, as noted in #64 (closed). Changes include:

• switch to using boost::spirit::qi which is maintained vs. boost::spirit::classic which is not.
• templated functions where appropriate for the new GenerateVector function
• moved to using separate .h and .cpp files for improved compile times
• doxygen documentation added

Depends on !841 (merged) to be merged first.

Closes #64 (closed)