Log Message:
x11/libxcvt: import libxcvt-0.1.0

libxcvt is a library providing a standalone version of the X server
implementation of the VESA CVT standard timing modelines generator.

libxcvt also provides a standalone version of the command line tool
cvt copied from the Xorg implementation and is meant to be a direct
replacement to the version provided by the Xorg server.