Add indexer_language to change stemmer for xapian FTS indexer Nagy Gabor asked how to enable the hungarian stemmer in roundup. This required editing indexer_xapian.py replacing hardcoded "english" term. This value is now exposed in the config file under [main] index_language. This only works for xapian currently.

[run]

# ignore the dist utils. They are not part of the code base
# we are going to test. They are used by maintainers only.
omit = roundup/dist/*