Fixes ignored unit tests

Also, prefer ServletLoggingFilter.X_VOODOO_RESPONSE_ID over
LoggingFilter.X_VOODOO_RESPONSE_ID
Refactored the LogFilter and dependencies

Switch from System.currentTimeMillis() to com.google.common.base.Stopwatch

Switched from PowerMock/EasyMock to Mockito.
Upgraded Jetty.
Upgraded Guava.
Upgraded JUnit.
Explicitly declared Javax.Inject, Guice, and Guice Servlet.
Explicitly declared Yammer Metrics core and annotations.
Removed jetty-annotations.

-- Logging
Added log4j-over-slf4j.
Added jcl-over-slf4j.
Added logback-core.
Added logback-classic.
Removed slf4j-log4j12
Provided a logback.xml file.