Update license_check.sh: catch unknown
Update license_check.sh: catch unknown

Update license_check.sh to check good/bad/unknown for each license.
- Fix some comment language
- Report uknown licenses (not in good or bad lists)
- Add '^$' to badlist.

gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab