- Storing a number of common functions into a separate file.

- Removed keys from search path. It all is based on query string.
- Added option in module settings to select search page path.
- Added options in module settings to customize excerpts for search results.
- Added a check connection page to help us diagnose configuration issues.
- Changed XMLPipe document, again. We now store the vids. All existing indexes
  get invalidated and need to be rebuilt.
- Refactored almost everything related to the search form, so it now becomes a
  bit more modular.
- Added basic tagadelic support. There is a single block with options to set
  number of tags, levels and sort order.