R mode in Chamo

A R mode is now available for Chamo, as a separate snippet. By now, this mode has only one key binding, to call the "r_eval" command. This command sends the contents of the active view to a background R process. The output of this process is displayed in the "outputs" window. Other commands can easily be defined the same way to interact with other programs (see the details).

If some text is selected in the view, then only this text is sent to the R process. Closing the R output tab in the "outputs" window closes the R process. When the "r_eval" command is executed again, a new process is created. If the command is executed and the R process is still running, then it is used and no other process is launched.