* remove more Riemann solver stuff

* remove non-existent export

* evict riemannsolver.jl and broadcast_[volume,faces,bdry]!

* evict Riemann solver related stuff from SRHD

* evict Riemann solver related stuff from EulerEq

* evict Riemann solver related stuff from ScalarEq

* convert all in EulerEq

remove unrelated file

* convert all in ScalarEq

* re-enable srhd_smooth test

update srhd_smooth reftest

* evict old broadcasting methods