Ajax DataLayer Integration

Thanks for the patch, works well.

- Added some documentation
- Fixed drupal_get_path() deprecation
- Nits like code style, docblocks and the one from #10
- Proposing to change the name of the command from PushCommand to DataLayerPushCommand as there are often multiple commands so we have a bit more context

Leaving to needs work for the tests.

Version 2.0.1 of the module includes lots of code that patch #16 introduces. I've cleaned the patch down to the last remaining change.

Update patch - small correction.

I broke the patch file naming convention, so added another patch file update.

I made a mistake in my comments above. I hadnt realised I'd tried patch #16 some time ago and I already had the changes so thought the module's been updated include some of the changes. Patch #16 is still the correct one here. Sorry for spamming this thread!