TODO: align default value of cutchars with rxvt.1.pod and add it as a fallback in perl 'selection'
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=377194
+ - expect major compatibility issues and please test and report.
+ - converted from the veritable io manager event loop to
+ the high performance libev (http://software.schmorp.de/pkg/libev).
- fix a serious bug while setting the XIM destroy callback
on (typical) 64 bit systems.