Gradle file modified to enable UI testing (TestBench), see #188

Moved common tests to testapp from demo, closes #188
removed legacy values from StandardPageKey, rewrote
DefaultLoginExceptionHandler and DefaultLoginAttemptLog

See #181.  Changed method of specifying dependency on test code from
another project to:

	//uses some code inherited from V7 subproject tests
	testCompile project(":V7").sourceSets.test.output

This has a quirk - it requires that the dependency (V7 in this case) has
a folder src/test/resources, and for Git to keep it, a file within it.

Reduced web.xml to minimum by using @WebListener