Fix compiler and lint warnings

[choefele]

As discussed in #52, I fixed the compiler and build warnings.

Most commits are straight-forward. The changes to PointQuadTree and PolyUtil are covered by unit tests.

Notes:

• As mentioned by you, the usage of the deprecated class Point is intentional, so I suppressed the warning
• Handler leaks: the reference to the outer class creates a cyclic reference as long as the instance is alive. However, since instances of these classes are short-lived, it doesn't create a memory leak. For this reason, I disabled the warning instead of refactoring the class.

Please have a look, thanks.

[broady]

I'm not convinced this adds very much :)

I think we should at least set the size to 4.

Could you also indent the lines above with spaces instead of tabs?

[choefele]

I updated PointQuadTree to use spaces instead of tabs

[choefele]

Yes, agree that ArrayList doesn't add much, but there doesn't seem to be a way to initialize an array of objects that have a generic parameter. Alternative would have been to suppress warning, which I think is worse.

[broady]

Thank you for all of your contributions!

I forgot to ask - have you signed the Google CLA?

[choefele]

I submitted the request, but haven't received any confirmation (if there is any)

[broady]

I don't think there's a confirmation - so, thanks!