misc changes, bugfixes and tests ...

- provide Response object in WebbException
- downgrade JUnit-Tests from 4.x to 3.8 (for Android)
- add tests running in Android emulator
- add capability to uncompress gzip/deflate encoded download stuff (+Tests)
- add tests for error cases
- modify Date headers (do not use GMT, but UCT)
- add tests for timeout handling (read timeout, connect timeout)
- api-test-server: option to switch logging of headers (in/out) on/off
- added many tests; split tests between mocked/not mocked (for Dalvik)