Multiple python versions (#42)

* Support multiple Python versions in single build

* RPATH + Split up config into config and runtime

* pybind11 submodule

* Docker build updates

.gitmodules

@@ -19,3 +19,6 @@
 [submodule "external/papi"]
 	path = external/papi
 	url = https://bitbucket.org/icl/papi.git
+[submodule "external/pybind11"]
+	path = external/pybind11
+	url = https://github.com/jrmadsen/pybind11.git