Add PlexClientPlatforms and PlexMediaContainer key
Remove language file and unnecessary module imports
Sharper icon
New background art; remove some Log()s
Excluded Roku client platform
Automated changes:

 - Removed useless plist key 'CFBundleVersion'
 - Removed useless plist key 'CFBundleDevelopmentRegion'
 - Removed useless plist key 'CFBundleExecutable'
 - Removed useless plist key 'CFBundleInfoDictionaryVersion'
 - Removed useless plist key 'CFBundlePackageType'
 - Removed useless plist key 'CFBundleSignature'
 - Removed useless plist key 'PlexPluginMode'
framework 2.1 update