[readme] swig 3.0.5 on ubuntu
[readme] swig 3.0.5 on ubuntu

SWIG 3.0.5 is not available through ubuntu repositories (not even in Ubuntu 15.10). I made a corresponding update to the ubuntu instructions.
opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core