Memo creation speedup!

There has been a cumulative problem with slowdown of new memo creation. I discovered that it had to do with the caching of the tag sidebar. Essentially, the expiration of this cache gets slower and slower the more cached items there are (since a new tag will expire a bunch of cached items, I use a regular expression and it loads the names of all cached fragments in order to apply the regexp).

By removing the caching it now takes less than a second to submit and create a memo.