Add Android XML (Tested with Layout Files, but should work with others)

Includes ability to use Hook comments to put widgets in a branch before
or after other widgets in the same branch.

Example of a before (android id in ????), just change to after
<!-- @start before android:id="@+id/?????" -->
XML Nodes here
<!-- @end before android:id"@+id/?????" -->
Altered Hook fstnode type
Currently, if the base version of the XML has a hook comment, this will
be outputted as another XML node. Will change soon to output back to a
hook comment.