[Tails-dev] Switched to IBus in squeeze too, please review

In branch "bugfix/ibus" in my repo "winterfairy/tails", which is based on
tails testing branch, there is patches that replaces SCIM with IBus, much
like I did for wheezy.

The most important reason for this is to fix bug #6206, which made it
impossible to use pinentry when logging in with Chinese, Japanese or
Korean.

This also fixes all points in bug #5624, I believe.

There was some uncertainity whether IBus works well in squeeze. All input
methods I tested, in all applications I tested them in, for all languages
I tested, worked just like I believe they should. Not a single crash or
unexpected behaviour. If there is unstability, it will probably not show
itself unless used by experienced users for a longer time.

I still believe switching is the right thing to do, as SCIM makes GnuPG
almost unusable. And we are switching to Wheezy soon enough anyway.

I also added bopomofo for chinese, as it seems to be more popular than
pinyin in some regions. This I also did in the branch "bugfix/ibus-wheezy"
in my repo, so it need to be reviewed and merged again too.