Memoize wildcard query

[Ryan Bates]

The wildcard query can be somewhat slow and is often performed multiple times per search. To improve performance it is more efficient if this is memoized. Something like:

class Xapit::AbstractQueryParser
  extend ActiveSupport::Memoizable
  memoize :wildcard_query
end

This has a very strong reliance on ActiveSupport which I may not want.

[Ryan Bates]

I am closing all issues because I have rewritten Xapit and want to focus on immediate bugs with this new version. If you find this issue still relevant, please comment here or open another issue and I'll take a look at it.