#6 Update to use gaim prefs framework instead of custom file

[Daniel Atallah]

I have updated gaim-encryption to deprecate the use of
the encrypt.prefs file (the old settings will be imported
and the old file deleted after the first use).

The new settings are stored in gaim's prefs.xml, using
the standard gaim plugin notation.

I also updated any strings (that i noticed) in the
modified files that should be gettextified.

[Daniel Atallah]