Mk/Uses: always use colon for build/run suffix

Most USES use a colon for build/run(/test) suffixes. Change kde.mk,
qt.mk and pyqt.mk to do the same, and update all ports using that.

Document in CHANGES.

PR:			266034
Exp-run by:		antoine
Approved by:		tcberner (mentor)
Differential Revision:	https://reviews.freebsd.org/D36349

Remove WWW entries moved into port Makefiles

Commit b7f05445c00f has added WWW entries to port Makefiles based on
WWW: lines in pkg-descr files.

This commit removes the WWW: lines of moved-over URLs from these
pkg-descr files.

Approved by:		portmgr (tcberner)

Add WWW entries to port Makefiles

It has been common practice to have one or more URLs at the end of the
ports' pkg-descr files, one per line and prefixed with "WWW:". These
URLs should point at a project website or other relevant resources.

Access to these URLs required processing of the pkg-descr files, and
they have often become stale over time. If more than one such URL was
present in a pkg-descr file, only the first one was tarnsfered into
the port INDEX, but for many ports only the last line did contain the
port specific URL to further information.

There have been several proposals to make a project URL available as
a macro in the ports' Makefiles, over time.

deskutils/todour: update the port to version 2.21

- Added scrollbars in settings dialog
- Added icons in Debian package build
- Slap icon on the window when supported

deskutils/todour: new port had been added (+)

Todour is a cross-platform application for handling todo.txt files.

PR:		260243
Submitted by:	mizhka