Working towards fixing mvn install compile errors for Java 8

[daveyarwood]

See discussion in #31. I thought I would submit a PR for the fixes I've done so far, working towards getting mvn install to work on the develop branch. I'm using Java 8.

This PR includes the java8 branch, which fixes the "Unable to get XClass for ..." errors.

findbugs still found one bug which causes mvn install to fail:

[INFO] --- findbugs-maven-plugin:3.0.5:check (default) @ javaosc-core ---
[INFO] BugInstance size is 1
[INFO] Error size is 0
[INFO] Total bugs: 1
[INFO] Class com.illposed.osc.OSCMessageEvent defines non-transient non-serializable instance field message [com.illposed.osc.OSCMessageEvent] In OSCMessageEvent.java SE_BAD_FIELD

I'm punting on fixing that on this branch. On the up side, I am able to get mvn install to succeed if I temporarily remove the fixbugs plugin from the pom.xml, so it isn't really blocking me at this point.

[hoijui]

included in branch develop as of now. thanks! :-)