Bugzilla import mangles non-ascii

Problem:

Our bugzilla system uses shift-jis for encoding japanese strings. The bugzilla import tool assumes ascii (or something else) for the data.

We develop applications in japanese, and the applications display error messages in japanese, all of these have been mangled.

Fix:

Add a field to the Bugzilla Import form that allows the administrator performing the import to set a character set to convert from.

Add code to the bugzilla import class that translates from the specified character set to UTF-8 as the data is imported.