Major Changes

Add support for Emby media servers (#297)
- Emby functions almost exactly like Plex, and both can be utilized at once (with some minor changes)
  - If both Plex and Emby are specified, then each library in a series YAML file's libraries section must specify a media_server attribute of either emby or plex so that TCM can determine which server the library applies to
- Title cards can be automatically uploaded to Emby, and images can be sourced from Emby as well (via image_source_priority)
- Series YAML files can be synced from Emby (just like Plex)
- Emby can be used as an episode data source (via episode_data_source)
- Episode watch statuses can be determined from Emby (applying any watched_style or unwatched_style)
- Enabled by specifying the emby section within your preferences file, like so:
```
emby:
  url: http://192.168.0.1:32400/
  api_key: abcdef123
  username: MyUsername
  verify_ssl: true
  watched_style: unique
  unwatched_style: grayscale
  filesize_limit: 4 MB
  sync: # sync options..
```
- The full set of options is detailed here
Automatically pass <<clean_title>> variable into all templates
- This is the path-safe title of the series, for example a <<title>> of 86: Eighty Six has a <<clean_title>> of 86 - Eighty Six (as colons are not permitted characters)
Change the default episode text color in TintedGlassTitleCard to SlateGray1
Change TMDb blacklist interval to 12 hours, from 24 hours

Major Fixes

Better handling of bad tags in Sonarr sync
- Exclusion or required tags that don't exist on Sonarr are now logged to the user
- If only a required tag is specified, and that tag doesn't exist in Sonarr, then reject all series instead of rejecting none
Handle corrupt TCM databases without random exits
- Corrupted databases are deleted and remade without requiring user intervention
Keep persistent database of series database ID's for better series matching on TMDb/Plex/Emby/Sonarr across runs

Let image_source_priority be overwritten per-series
Log all unknown arguments (likely extras) provided to mini_maker.py (should help identify inappropriate argument specification)
Report missing Specials content in missing file
Match series and episodes using TVRage ID (can be provided by Sonarr and used by TMDb or Emby)
Log each time a series YAML file is read (to potentially alleviate confusion when cards are not being applied)
When sourcing episode data from TMDb, no longer ignore episodes until 2 hours after they've aired (can be sourced immediately)

Only look for clean paths in FadeTitleCard, LogoTitlecard, and PosterTitleCard (i.e. remove illegal characters)
Only log successful image downloads when downloading images with fixer.py
Improve episode matching via database ID's
Reject negative TMDb retry counts - not really a "fix", these were being treated as 0