Upgrading Mousetrap

Moving up to the current version of @ccampbell's excellent keyboard
shortcuts library.
Expanding keyboard shortcut bindings

Per #227.
Remove search-related template items

Search won't be baked in until v0.9—this shouldn't have been brought
over from the beta site.
Support a flexible format for gathering globally scoped definitions

Per #207.
URL encode the section identifier

Per #187.
Have structure_unified refer to structural "identifiers," not "numbers"

Per #187.
Switch to label-agnostic structural labels

Basically an extension of #22.
Turn every use of structure "numbers" into "identifiers"

Per #187.
Update comment to be agnostic as to structural labels
Change structural column names from "number" to "identifier"

Reflecting database name changes, per #187.
Remove structure_unified references

These have no place in the database creation script, since the view is
defined dynamically, based on the actual structure of the legal code.
Rename structure's "number" column to "identifier"

Per #187.
Change all structural "number" variables to "identifier"

Per #187.
Updating version number
Capitalize boolean
Rewrite inane comment
Fix minor bug in Parser::store
Move XML directory into /admin/
Lowercase booleans
Improve how text is broken into paragraphs

Eliminating an improbable arrangement of paragraph tags and replacing a
misused PHP_EOL with a more sensible method of breaking up text based
on newlines.