[Conkeror] Some conkeror regressions from 0.42

[Ævar Arnfjörð Bjarmason]

I upgraded from conk 0.42 to the git head that uses xulrunner yesterday:

* M-d (cmd_deleteWordForward) doesn't work in forms: Invalid command:
  cmd_deleteWordForward

* I have to press "f" to turn on the navigation links, how do I turn
  them on all the time like M-l used to do?

* When I download a pdf and choose "open" and provide no program with
  which I want to open it conkeror crashes. I.e.: google -> filetype:pdf
  -> click the first link -> Action to perform -> save/open -> open ->
  don't put anything in the form -> RET -> crash

On the up side:

* gitweb navigation via numeric links now works, though I have no idea
  why it was broken before.

* <s>M-space (sync X/conq clipboard isn't there anymore., how do I copy
  things to/from the X clipboard?</s> Yay the clipboard syncing appears
  to work automagically!