Added hyphen character to sourcemap match pattern, refs #15.
Added sourcesContent for input sourcemaps, refs #18.

Does not resolve existing failing tests, and does not add a passing
test (yet), because of the number of failures.
Lock at previously working version of source-map, version 0.1.31.
Merge pull request #19 from michaek/master

Adds hyphen to sourcemap match pattern and adds input sourcemap content to sourcesContent.