bash_completion: try to use bash3 features if they're available
This does NOT break completion for bash 2.05b (I haven't tested
earlier versions)
--- a/contrib/bash_completion
+++ b/contrib/bash_completion
@@ -166,4 +166,5 @@
}
-complete -o default -F _hg hg
+complete -o bashdefault -o default -F _hg hg 2> /dev/null \
+ || complete -o default -F _hg hg