Indexer searching for special episodes using query string

Added SpecialEpisodeSearchCriteria criteria to handle special episode search queries
Added method NzbSearchService.SearchSpecial() for season0 episodes
Added IIndexer GetSearchUrls() for doing text based queries
Special Episode parsing support in ParsingService

Added ParsingService.ParseSpecialEpisodeTitle
Added SeriesService.FindByNameInexact
Added EpisodeService.FindSpecialEpisodeByName
Added IsPossibleSpecialEpisode method to parse info
DownloadDecisionMaker will try to find special episodes if a parse fails or is a possible special episode
Fixes in response to code review
ParseSpecialEpisode now follows similar pattern to Map() method and accepts TvRageId and SearchCriteria
Fixed normalize episode title to handle punctuation separately from spaces and removed special episode words
Removed comments
Fixes for code review
Replaced + with space in special episode query string builder
Refactored retention spec
Fixed: SABnzbd test with fail if the API Key is wrong
Add existing series shows a loading message

Fixed: Message to tell users series are being loaded from trakt
Labels for add series options
Fixed: series/episode rating is 0-10
Fixed: command+T will not target search box in UI
Merge branch 'special-episode-search' of https://github.com/iaddis/NzbDrone into special-episode-search

Conflicts:
	src/NzbDrone.Core/Indexers/Omgwtfnzbs/Omgwtfnzbs.cs