Fixed double-declaration error.
Added 'pretty' log mode

Added special value for log_mode 'pretty' which uses Util::message for
printing colored output. Meant to be used in interactive mode, it's
the default in cf-sketch.pl.
log_level default to zero in interactive mode

By default set log_level to 0 in interactive mode, to prevent all
spuriour output. Gets modified accordingly by --verbose or
--veryverbose.
Added 'info' command

The 'info' command shows detailed information about a sketch. With -v,
it shows its API as well.
Fixed date.
dclib: add dctest.pm; epel, memcached, packages_installed: update tests to use dctest.pm