added search controller

very rudimentary for now:
* inefficient
* results rendering ain't pretty (no match highlighting, missing links
  for weekly statuses and comments - plus the code's not very DRY)
* only accessible manually (i.e. via the URL) for now
removed obsolete CSS

this appears to be unused
added search form to nav bar

caveats:
* the submit button looks out of place and might not be necessary (ENTER
  should suffice)
* overriding Bootstrap seems nasty, but inevitable (not sure why they
  float that element in the first place)
Merge branch 'search'