ceskatelevize.cz subtitles translator per Johan Baskovec

Guide :

- install the plugin
- open a video on https://www.ceskatelevize.cz (for example, https://www.ceskatelevize.cz/ivysilani/10117034229-168-hodin/220452801100209)
- enable the subtitles by clicking the gear on the bottom right corner, clicking on the dropdown below Titulky and selecting "Skryté titulky"
- play the video

When a subtitle appears, this plugin will :
- embed the Lingea dictionary in the page, below the video (in an iframe)
- display the current subtitles with a link for each word, each link searches for the word in Lingea
- display an history of all sentences. A "sentence" is a sequence of words that ends with ".", "?" or "!". Click on "→ Translate" next to each sentence to open it in Google Translate. The new window will automatically refresh when a new sentence is complete. Click on each word of the sentence to search for it in Lingea.


Known bugs :
- the timestamp is incorrect when multiple sentences are displayed in the same subtitle
- multiple sentences are detected when a sentence contain a dot (for an abbreviation ("s.r.o."), or ordinal number ("Karel IV."))