UI Rebuild

This release is largely under the surface improvements to the manticore codebase.

The user facing changes in this release are:

• HTML5 range control for setting party size and level. No more typing.
• Pagination of results.
• Results are grouped by the monsters included and when there are multiple variations just differing by number these are listed as variants. Just tap the link to expose the alternatives.
• A given encounter can have a maximum of 7 different monster types.
• Territorial monsters (currently hardcoded to dragons and master vampires) won't appear in the mix with other territorial monsters.

For the developers reading the under the surface improvements come in two parts:

• It now uses reactjs for all the UI and all the previous implementation has been removed.
• Much of the work of accessing the datasources and generating encounters happens on worker processes. This should mean that the UI is overall snappier and should be easier to work on.