[openlp-dev] Support multiple languages

[Simon Hanna]

Hi there,

Since my church will only switch to OpenLP if it supports presenting two
languages, I decided to work on it.

I'm happy to announce that I finished the heavy lifting on the song
editor. So I would appreciate your feedback on it. The code lives here
https://code.launchpad.net/~thelinuxguy/openlp/multi-language

No database migrations need to be done, and all the changes to specify
the languages are reset once an older version of openlp(which silently
ignores what language a verse is in) overwrites the language
information, so yet get a "clean" database.

Since I'm not doing any database migrations the "primary language" is
just the first language encountered and changing it doesn't actually get
saved. (This will change in the future)

There's still a few things concerning the editor that need to be addressed:

- Not everything is translatable yet and some of the strings I used are
subject to change

- How to handle verse order (This currently only picks up the "primary
language").

- What language information should be stored in the database.

    - The primary language?

    - All languages so you can search by language?

    - How about Titles for each language? (Other information as well?)

- How to handle invalid (or unknown) language codes that are encountered


Since the points I mentioned above need discussion, and I don't have a
very strong opinion on them, I'm leaving them for now.

My next milestone would be the ability to choose one language that is
going to be presented and after that add support for two languages, ...