KIJIMR-19. Improve testing framework.

 - KijiClientTest provides a default test configuration.
 - KijiClientTest provides a local temporary directory.
 - KijiClientTest exposes a test ID with class and method name.
 - Force a GC after each test, to trigger resource finalization.

Signed-off-by: Lee Sheng <lsheng@wibidata.com>
Pass at paging

Conflicts:

	kiji-schema/src/main/java/org/kiji/schema/impl/KijiColumnPager.java
fixing up broken tests and writing new ones
SCHEMA-169. KijiPager and KijiPaginationFilter Tests.
Small change to map key.
All unit tests pass.
More integration tests.