To Do
~~~~~

- Fix NOT operator.
- Needs to be able to search multiple files at once.
- There may be some problems with merging more than two
  large files at once...
- It would be simple to add in a substring search, like *this*
  with a fast strstr, but Kevin didn't have time and Miles
  hasn't looked into it yet.
- The parser needs to be a bit more robust...
- Multiple custom field searches.
- SWISH needs a man page.
- I need to double-check if multiple FileRules in multiple config files
  overwrite. They shouldn't...
- Temp file cleanup could be better.
- Could check for overwriting existing files.
- Proximity, stemming, soundex.
- File filtering.
- Implement a memory limit option; SWISH then saves to disk every once
  in a while during indexing...
- Run SWISH as a server?
