Examples multiplatform build

[notthetup]

Cleaned up the examples a little.

• A new top-level Makefile to bundle and clean
• Support for building the Examples.tgz on any platform (removed hard-coding for Tegra/ARM/Linux).
• Added a top-level Readme for explaining how to create bundles.
• A bunch more .gitignores to ensure that there are no laggards in the fs after a build.
• Remove committed jar files.