Fix BintrayGenericUpload for Java 6.

The fixed length streaming mode was failing on Java 6 when uploading packages
to Bintray. It's not clear why, but I've disabled this mode since I don't
believe it offers significant advantages for our use case, and Java 6
compatibility is still worthwhile I think.

I have also improved the error handling in the `BintrayGenericUpload` task
because user's were left wondering why they were getting 400 responses. The
task now displays the body of the response from Bintray, which includes the
explanation of why the upload failed.
Add some help to lazybones-project template build file.
Bump plugin to 1.0.2 and update everything that uses it.