Makefile.options.OpenBSD tweaks

[emulti]

Thanks for the updates to Dillo Plus! Some notes from testing:

On recent OpenBSD, the default location for Manpages of non-base packages is /usr/local/man.

So Makefile.options.OpenBSD should contain:

MAN_PATH = $(PREFIX)/man/man1

Also, the OpenBSD port of standard Dillo uses /etc/dillo for the config directory:

DILLO_ETCDIR = /etc/dillo/

would match this and avoid the dillorc and other files that may already be in /etc/dillo from conflicting with those in /usr/local/etc

The dillo.desktop and dillo.png in the dist folder do not seem to be installed by the Makefile. On OpenBSD the locations for these would be /usr/local/share/applications and /usr/local/share/pixmaps respectively.