Add hotkeys for annotation tools.

[XMB-7]

This would significantly enhance the convenience for heavy annotation users.
For example, set num or alt+num,

[gildas-lormeau]

Thank you for the suggestion. Note that some shortcuts already exists. num6 and num7are respectively Ctrl-Z and Ctrl-Shift-Z. num8 is Ctrl-S and you can print the page with Ctrl-P. I think it is a good idea to implement at least num1 and num2. Maybe the it could combined with Ctrlfor toggling features.

[XMB-7]

Thank you for considering adding shortcuts for annotation tools. In my opinion, num2 and num3 are the most helpful ones for the purpose of continuous highlighting. It would be even better if alt+z and alt+shift+z could be added specifically to undo and redo highlighting operations.