Refactor double-quoted string tests.

Remove the word highlight from test descriptions. Refactor common scope tests into a single test where applicable. Use the word tokenize in preference to tag. Add more detailed descriptions of how elements should be tokenized.
Remove Python magic function sections from grammar.
Remove Python magic variables section from grammar.
Remove Python style docstrings from grammar.
Remove references to built-ins from grammar.
Merge PR #18 into master. Refactor tests.
Add missing -s to function name in failing test.
Change all  to .
Merge pull request #18 from jagrem/master

Refactor tests and remove Python 'magic'

Closes #6