Fix typo in German translation

Fixes #1901
Make it possible to upload and test new .lang files directly into Showtime

Access this feature at http://showtimehost:42000/showtime/translation
Fix build break
Add support for MPL subtitle format

Fixes #1870
mpl: Check that we are at start-of-line when treating '/' as italic:on
Update pl_PL.lang

Forgot about mining translation :) Now it's fixed.
Make it possible to set read timeout in VFS
Add MP_PLAY_CAPS_FLUSH_ON_HOLD (Useful for Radio steraming)
Propagate fap_set_read_timeout() in fa_buffer
Add support for 'radio' media_pipe type
fa_open(): Replace 'struct prop *' with 'struct fa_open_extra'

This makes it possible to add more special args passed to various open functions
Add more control over HTTP requests backing file ops.
Add prop update packets to the media_pipe

This allow properties to be updated in sync with the audio stream
radio.view: Display 'radioinfo' property
Add icecast client

To play icecast/shoutcast streams just prefix the URL with icecast:

It will autodetect if it's a audio stream or a .pls playlist.
For the latter it will select a random stream and rotate among
them if connection fails

Fixes #1826