a few tests of english ops re: https://github.com/brownplt/pyret-lang/pull/220#issuecomment-48685416
slightly more accurate dependencies on tests
parse-test also depends on these two files
Prevent - at end of identifiers, and add tests to warn on regression.

No regex constructions that aren't already in use are used in this fix.
Hopefully this implies no new browser incompatibility.