Changed the default output appender to be a PrintStream

Previously the default output was an OutputStreamWriter. Since this is buffered
it resulted in test output being buffered making watching the test output in
real time impossible. Now we use a PrintStream which is the type that the
System.out stream is anyway, while still retaining the fix intoduced to make
the Appender's close() method a no-op.
Added test that ensures that output to System.out is not buffered
Merge pull request #721 from orionhealth/make_standard_out_non_buffered

Make standard out non buffered