fix NPE in Field.getAnnotations
Merge pull request #234 from dicej/field_getAnnotations

fix NPE in Field.getAnnotations
CP: Properties.stringPropertyNames()
CP: StringBuilder.append(char[])
Merge pull request #237 from pcarrier/sb

CP: StringBuilder.append(char[])
fix Misc test failures

The Misc test was failing when run as "make input=Misc run" since
test-flags did not include $(build)/extra-dir in the class library,
leading the ClassLoader.getResources test to fail.

Also, the UnknownHostException test was not reliable -- some ISPs
(mine included) return DNS matches for bogus hostnames, defaulting to
the IP address of a webserver intended to help users with name
resolution problems.  That's dumb, I know, but I'm guessing I'm not
the only person with a dumb ISP, and it seems better to just remove
the test than make people think Avian is broken when it's really just
their DNS server that's broken.
Merge pull request #238 from pcarrier/PsPN

CP: Properties.stringPropertyNames()
Merge pull request #239 from dicej/misc

fix Misc test failures
Add basic dockerfile for avian build
fix UTF-8 docker ENV vars

Before this, for some reason Java defaults to non-UTF-8 file.encoding.
This is problematic because the Strings test effectively asserts
the opposite, which makes 'make jdk-test' fail.