i18n: use util.pconvert() instead of 'str.replace()' for problematic encoding
some problematic encodings use backslash as part of multi-byte characters.
util.pconvert() can treat strings in such encodings correctly, if
win32mbcs is enabled, but str.replace() can not.
mq: make qprev return the previous applied patch (
issue3245)
The current behaviour is to return the previous one in the series but at the
same time the implementation is buggy because it does not take guarded patches
in account.
mq: fix qnext when all remaining patches are guarded
When all remaining patches are guarded, qnext used to return the last of the
queue anyway.