Show keynames

A small patch on v0.18 ( debian current version) to allow users to disable hotkeys labels, which are really annoying for some keys ( some shows "world_something" and hide everything behind them).

The second patch is a very small change which consist in moving duplicated code into a function. Could be extended to controls other than labeled checkboxes (and finish to divide a bloc of 400 lines in more or less 40).