Redid some of the ignored UniqueIndexAccessorCompatibility tests in terms of UniqueConstraintCompatibility.

The populating IndexUpdater test, however, is not equivalent to the test it replaces, because our
pessimistic concurrency control seems to make some of those particular scenarios in the old tests,
impossible to hit through the public API.

The work of rewriting the tests is not yet done. This is just a step of the way.
Implement replacements for all the ignored index compatibility tests
Remove unused code from unique indexes.
Don't add a node to empty graphs in live console.
Increate test timeout hoping that it'll be less likely to fail on the virtual build servers.
Merge pull request #1944 from nawroth/2.0-maint

Don't add a node to empty graphs in live console.
Add CypherTestSuite that extends FunSuite with the right RunWith annotation
Use a more verbose error message when index and label scan hints are not applicable
Merge pull request #1934 from chrisvest/duplicate-number-index-tests-fix

Duplicate number index tests fix
Merge pull request #1963 from jakub-/cyphertestsuite

CypherTestSuite
Merge pull request #1958 from boggle/2.0-msgfix

Use a more verbose error message when index and label scan hints are not applicable
Fix typo
Allow using undirected relationship patterns in MERGE