Merge branch 'develop' of https://github.com/stan-dev/stan into develop
added update to makefile for eigen asserts and fixed three tests
updating test for check_simplex_test so it passes with EIGEN_NO_DEBUG
fix factorU test
updating bfgs_update test
fix bfgs update test
Merge branch 'bugfix/issue-904-eigen-assert-bugs' of https://github.com/stan-dev/stan into bugfix/issue-904-eigen-assert-bugs
Merge pull request #940 from stan-dev/bugfix/issue-904-eigen-assert-bugs

Fixes #904. Bugfix/issue 904 eigen assert bugs