Clean up e2fsck problem description messages for typo's and to make them
easier to understand (sorry, translators).

Add new @m (multiply-claimed) and @n (invalid) expansions for e2fsck
problem descriptions.

Add Dutch translation, and update French translation.

Add an explanation of how the @-expansion and %-exapansion works in 
e2fsck/problem.c to make life easier for the translators.

Synchronize and update po files.

46 files changed