Fix bash_completion on Solaris TK Soh noticed that the awk that ships with Solaris doesn't allow you to define new functions. According to http://www.shelldorado.com/articles/awkcompat.html it looks like it also doesn't have some other stuff that we were using, like deletion of an array element and gsub. Rewrite the parsing of hg --debug help to work around that. This version doesn't filter aliases that are simple abbreviations for debug commands (not a big problem, since there are none right now).

refactor the dodiff optimization