[sailfish-browser] Add link validator and tests for it
[sailfish-browser] Do not save unnavigatable urls to database. Contributes to JB#15601
Rename manual mailto test to more generic url scheme tests.

This commit also adds sms, tel, and geo manual test cases.
Merge pull request #7 from rainemak/improveHistory

Do not save unnavigatable urls to database. Contributes to JB#15601