Initial commit. Move to XSLT 2.0 in order to use regular expressions

In the latest round of remediated metadata, the following can be
found:

<item_-_MODS_-_FormGenre_1>printed ephemera</item_-_MODS_-_FormGenre_1>
<item_-_MODS_-_FormGenre_1_-_Authority>AAT</item_-_MODS_-_FormGenre_1_-_Authority>
<item_-_MODS_-_FormGenre_2></item_-_MODS_-_FormGenre_2>
<item_-_MODS_-_FormGenre_2_-_Authority></item_-_MODS_-_FormGenre_2_-_Authority>

To handle the new ..._-_Authority element, the old templates that used
start-with() do not work correctly since it does not look at the ending
to different between the main element and its authority. Easiest way
to do this is with regular expressions, which require XSLT 2.0