Transcript refactoring & tweaks
- Change transcript button style when transcripts are not available
- Add hidden transcripts for screen readers
- Add license header
- Shift toggle buttons to hook
- New class for storing episode information
- Comic pages should be able to handle 3-letter-locales now (but not the language selection menu yet)
Note about the refactoring
When plxMyMultiLingue gets constructed, the information about the episode is not available yet - we need a hook for that. So, I am using a trick called late initialization - the object is constructed immediately, but then initialized later by whichever hook happens to be called first.
Closes #40 (closed)