Amr examples

[mclarsen]

This includes :

• a simple example of a small domain with a single child.
• a complex example that can create an arbitrary nesting of julia

[coveralls]

Coverage increased (+0.3%) to 86.384% when pulling 7d3e50d on amr_examples into 13d33e0 on master.

[cyrush]

looks great, added two naming comments.
Also, we want to move all of the julia stuff (even the non-nestset examples) into a separate source file to help keep them contained.