Xwrits + activity logging

This is a very slightly modified version of xwrits. It now contains additional code for writing a time stamp every so many key/mouse actions into an activity log which you may specify with the new command line option '--activity-log'. You could use such a log, for example, to produce your monthly working hour report, etc. This modified version is based on xwrits-2.11. Xwrits was written by Eddie Kohler from MIT. The code hereby is a miscellaneous enhancement of this great software.