no similarity matching by default
Minor fixes in install.

I seem to keep quoting things mysql doesn't want quoted.

Also fixed logic in reporting table migration successes.
Don't try to install constraints where not supported.

Skip most reference and constraint trigger migrations on MyISAM tables.
Merge branch 'master' of https://github.com/thylacine/Feed-on-Feeds
Merge branch 'master' of https://github.com/RomanSixty/Feed-on-Feeds

Conflicts:
	classes/fof-prefs.php