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()
Change assert in test_quoteforandroid() for checking new behavior
Add test_unquotefromandroid() test
Replace ' chars with \u0027 in Android DTD
Call quotefordtd() from quoteforandroid()

This will provide all quoting for regular DTDs also in Android DTDs.
Add unquotefromandroid()

This will allow roundtrip conversion for Android DTD files using Android
specific escaping and unescaping.
Add support for converting Android DTD files to PO

Fixes bug #2480.

This will allow to do roundtrip tests for Android DTD files.
Fix mixture of tabs and spaces
The active state is now more carefully managed

By default if po2moz runs it it will default to marking as active. With
po2mozlang you have a command line option.
If a unit is fuzzy revert to empty string

This way the .lang store will use Source in its output but will not mark it
with the {ok} flag.
Test correct working of {ok} marker

The {ok} marker indicates a string that is the same as source but is still
translated.
Handle multiline comments

Ensure we preserve multiline comment layout
Add tests for quoteforpo

The last test is the critical one.  When line length sits on 77 chars then
somehow linewrap drops the \n that we had in before.  Very strange corner case
this one.
Fix readding \\n to manage len(ln) == 77

At 77 chars we end up with len(ln) == 2.  But the ln[-1] == ''.  And 'if
ln[-1]' evals to False so we don't add back the \n

Took an age to debug this. Hopefully it doesn't introduce some other issues.