templater.firstline should handle empty strings

hgweb: fix unbundle. After the WSGI changes, even if a push over HTTP succeeds, apache complains about "Premature end of script headers: hgwebdir.cgi" and returns a "HTTP Error 500: Internal Server Error", making the local hg abort. The change to either of the files touched by this patch is enough to fix this, but I think changing both is a more robust solution.

Fix push over https. Without this patch, python gives me a TypeError: write() argument 1 must be string or read-only buffer, not file

Allow http://user@example.com URLs (i.e. without passwords)

hg.py: move exception handling code to try to avoid hiding errors

help: add help to mq extension

help: make "hg help EXTENSION" work

Adjusted test output to changed abort message of 'hg merge' (from 0229ff95faec)

merge with crew.

Disable automatic line endings conversion on windows The rationale behind this is that such conversion implies a particular situation in which all files in the repo are terminated by only LF. This is documented nowhere and it bit me sharply when I upgraded. Furthermore, it works on the assumption that a file containing no NULL characters are actually a text file. Therefore it cannot guarantee that no binary file will be harmed in the process. Currently, if a file already contains CRLF line endings when it is copied to the working dir from the repo, then the version in the working dir will be corrupted by an extra CR. I'm working on a patch that will turn this into a warning. But as a side effect, committing such a file back will strip it from its CR. In all case, unrequested data modification can occur under the feet of the user, which is bad(tm), ihmo.