command to load a specifi app with custom content id

tts: add voice-name cmd argument

cmd/watch: json output and connection retries

http server and file media type from magic headers in binary

Do not compile for darwin-386

seek command for Plex

custom transcode command and change dial timeout to something more re…

…asonable

seek-to command, bug fixes with media playing locks and useful id for…

… youtube playing media

mute and unmute commands

all: add ApplicationOption's and a way to get cast dns by name

Added ApplicationOption's which can be used to configure the
application.

Changed to use a variable for 'connectionRetries' instead of the
hardcoded 5. Can also be configured with the ApplicationOption.

New method in 'dns' to quickly and easily get a cast dns entry by name.