Easy fix problem with multitarget hxml files and autocompletion

[grepsuzette]

Hi, I noticed a problem which should be easy to fix, but took me a while to detect.
When you have several parts in a hxml file, you can separate them using --next, and specify a line

# display autocompletions

so that vaxe knows which one to use.

However whenever you have a --next without a comment vaxe will (incorrectly) use that as a legitimate --next.

E.g. this will fail:

--next
# This should be placed after a --next, not before    <--- Fail here because --next in a comment not discared
# show completions

I fixed by not using dashes within a comment, but I thought it might be good to fix this for other users.

Thanks for the good work on vaxe :)