Add simple functional test for format
Add ## active ## flag handling

We understand the active flag so can parse it as needed. By default we'll
leave iin its current state.
Split up tests for quotefordtd() and unquotefromdtd()
Add commented code for escaping and unescaping < and > characters
Add new asserts in test_unquotefromdtd()
Add assert in test_quotefordtd() for checking singlequoting around string
Add docstring to test_quoteforandroid()