standalone refactor
can append cache vars
something works
libagents now installs correctly.  need to fix tests
updated test input files
updated use cyclus to support tests
adds a base class for mixin or composed classes managed by agents
prevents in source builds
some minor cleanup issues
Merge branch 'gidden-mixin' into develop
Merge branch 'oos' of https://github.com/gidden/cyclus into gidden-oos
Merge pull request #874 from scopatz/libagents

Libagents
Merge branch 'develop' of github.com:cyclus/cyclus into develop