fix autocomplete eating prefixes
legacy support for /note/history

from http://danbooru.donmai.us/note/history?user_id=32729 to http://danbooru.donmai.us/note_versions?search[updater_id]=32729
fixes #1829
Merge branch 'master' of https://github.com/r888888888/danbooru
fixes #1832
fixes #1833
cache intro page
potential fix for #1818
potential fix for #1818
potential fix for #1818
potential fix for #1818
update version
add post update count to user listing
remove unused commit=Go parameter from post searches
hide certain elements by default to prevent flickering; fixes #1357
fix metatag case sensitivity
Merge branch 'master' of https://github.com/r888888888/danbooru
fixes #1842
fixes #1840
artist excerpt