Optimization to speed things up and make (many) fewer requests.

Change log:
* When not in manual mode, run searches and score sequentially. Short circuit when we find a "perfect" match (score of 98 or more).
* Increase cache times (went with CACHE_1WEEK which seems fine for movie results).
* Request compressed XML.
* Only fetch additional details (canonical name/year) for PlexMovie matches whose "percentage" is above a threshold. Currently set to 80.
* Bound penalty for incorrect year on hash results (plus a bunch more scoring logic fixes).
* Refactored to use consistent searching and scoring for both hash and title/year searches.
* Extracted some tunable values for PlexMovie scoring.