add history search to qtconsole

[timmie]

Enable search backwards in history.

In terminal this works with CRTL+R

[takluyver]

Thanks - this is already tracked as #1393. Note that you can get something similar by typing in part of a command, then pressing up for prefix search or shift+up for substring search.

[timmie]

UP & SHIFT UP are not documented in but in the console help accessible via the HELP menu:
http://ipython.org/ipython-doc/rel-0.12/interactive/qtconsole.html

I suggest to have something like:
ipython.org/ipython-doc/rel-0.12/interactive/htmlnotebook.html#keyboard-use

[takluyver]

Good point. The docs are in this repo, would you like to make a pull request?