Added support for reverse variable matching

[nrktkt]

Addresses #2

Bumped Java version to 8

• Named capture groups not supported in 6
• I like to lambda

Added Either monad class to deal with repeated variables.

Currently this should support the majority of use cases, however more work can be done to better support level 4 templates.

Future work:

• Make matchParameters and matchSegments inspect each VarSpec for allowed characters
• Make matchParameters and matchSegments inspect each VarSpec for explode modifier
  • Currently multiple parameters will automatically become a list, regardless of presence of explode
  • Currently multiple segments are not supported
• Make buildMatchingPattern match more strictly, seems to work OK now but could result in issue reports later
• Integrate with existing test suites and generally expand testing.

[damnhandy]

Thanks!