clean forward_model docs; removed ForwardModel1; fix: observations in sum;
name in addModel now generated by default


git-svn-id: svn+ssh://svn.mystic.cacr.caltech.edu/mystic/mystic@750 968178ea-60bd-409e-af13-df8a517b6005
Merge branch 'master' of https://github.com/uqfoundation/mystic