- When providing alternative spellings to a query, do not
  prefix it with a package qualifier as the suggestion may
  not have any results. Correctly filtering is quite a bit
  of work, and clicking the alternative spelling will always
  also show the qualified hits if they exist (but also others).
  Seems good enough for now.
- Give user feedback when the query syntax was wrong.
- Package names in search results are now links to the respective
  package documentation.
- Experimented with excluding main packages and test files
  from index with inconclusive results. Code is present and
  can be enabled by changing a flag in the source. This needs
  some more work.

R=rsc
CC=r, dsymonds
http://go/go-review/1026033