Ignore .cache by default in .gitignore
Improvements to the /__middleman/ metadata pages.

Includes formatting/styling changes to clarify the data being presented as well as align styling with middlemanapp.com. Also adds features and fixes to the sitemap view to show ignored files differently, hide redundant information, print data/options as a hash instead of as array pairs, and to list out available locals defined on a page.
Merge pull request #1229 from bhollis/metadata

Improvements to the /__middleman/ metadata pages
Webrick should not do reverse DNS lookups

This prevents Middleman server from being terribly slow over network. Closes #1118.
Merge pull request #1232 from lolmaus/patch-1

Webrick should not do reverse DNS lookups
Include the destination_path in the instrumentation payload.