Rename legacy imjournal configs to have "imjournal" prepended.

	modified:   doc/imjournal.html
	modified:   plugins/imjournal/imjournal.c
Merge branch 'tmp' into v7-stable

Conflicts:
	plugins/imjournal/imjournal.c
fix imjournal doc after merging patch

... was changed in the interim, so the result of the merge was
sub-optimal ;)
doc: improve imjournal doc

most importantly, convert sample to new-style config format