Major code tidying

De-stringified the Widget code, restructured so that virtually all
injected code is held in `gmeResources.script`, and de-linted the
results.
Tidy up DOM

Avoid leaving unnecessary `<script>` elements in the DOM after script
insertion or JSONP / XHR calls.
Revert "Tidy up DOM"

This reverts commit 737357f44547557f9843417cd345d8402ab4bda8.
Tidy up DOM

Avoid leaving main script in DOM after insertion.
Freemap.SK support

Added Freemap.SK Slovak OSM map sources to the default list (not
selected by default).
Improve Google keyword search

Update Google search URI to get more hits on caches, by including pages
that were indexed with an old-style address.