Replaced android.test.InstrumentationTestRunner with...

Replaced android.test.InstrumentationTestRunner with com.zutubi.android.junitreport.JUnitReportTestRunner.

Create javadoc/ directory when doing "ant javadoc". Fixed installing debug builds with ant.

"ant -f tests/build.xml debug && ant -f tests/build.xml installt test test-report" compiles, installs, tests,
and saves output to tests/junit-report.xml.