bash_completion: be more careful about whitespaces
- use awk to parse the output of hg help.
- print one completion candidate per line
- print the debug commands after regular commands
(this eases the shell side of the parsing)
- don't print aliases that are simple abbreviations
(e.g. up/update, id/identify)
#header#
<title>#repo|escape# Changelog</title>
<description>#repo|escape# Changelog</description>
#entries%changelogentry#
</channel>
</rss>