Log Message:
Upgrade misc/screen to version 4.6.1

Version 4.6.1 (10/07/2017):
  * Fixes:
    - problems with starting session in some cases
    - parallel make install
    - segfault when querying info on nonUTF locale

Version 4.6.0 (28/06/2017):
  * Update Unicode wide tables to 9.0
  * Support more serial speeds
  * Improved namespaces support
  * Migrate from fifos to sockets
  * Start viewing scrollback at first line of output