Stop scrubbing @natthu's name from TODO's
Expose JavacOptions from DefaultJavaLibrary.

Summary:
To parse Java files, we need to be able to read the JavaCompilerEnvironment of
a JavaLibrary. This is stored on JavacOptions, so we add a method to expose
that.

This is a little bit dangerous, because the javacOptions member is actually
mutable, and we reset it for AndroidLibrary rules. This isn't trivial to
refactor away, because the Android parts need a classpath that isn't available
when the BUCK files are being parsed. It's not an immediate problem for us,
because nothing is changing the jcEnv member, but it *could* be a problem in
the future if we're not careful.

Test Plan: Just a new accessor method.
"Fix" linting error by commenting out new lint failures

Summary:
I'm not sure why this is causing "ant lint" to suddenly start choking, but we should be able
to lint cleanly. Since we're planning on revivifying the IJ plugin at some point, leaving the
code commented out so it's easy to figure out what needs to be done.

Test Plan: ant lint
Avoid using exceptions for flow of control.

Summary:
In Java, it's considered poor form to use exceptions to control the flow of control.
We used them briefly here since it was a nice way to get started quickly, but we can
determine at coercion time what the correct type is, so there's no need to use the
exception-based approach.

Test Plan: buck test --all
typo

Summary: Closes #107

Test Plan: Imported from GitHub; no strongly-typed plan
Refactor JavaFileParserTest to make it easier to add more tests.

Summary: In particular, make the JavaCompilerEnvironment static.

Test Plan: buck test //test/com/facebook/buck/java -f JavaFileParser
Fix local classes in JavaFileParser.

Summary:
Java classes can be defined inside of methods, and these local classes live in
a different part of the AST than regular classes and enums. JavaFileParser was
choking on them. Detect this case and skip it, since these classes are not
externally visible.

Test Plan: New unit test in JavaFileParser.
Fix JavaFileParser for files with no package.

Summary:
We were running into an NPE when we parsed Java files with no package
declaration. Handle that case.

Test Plan: New unit test.