Fix CSV output of matrices to be in column-major order, consistent with the header output..
Merge branch 'develop' into feature/fix-csv-for-matrices
Fix CSV output of matrices to be in column-major order, consistent with the header output..
Additional unit testing for CSV output of matrices.
Merge branch 'feature/fix-csv-for-matrices' of https://github.com/stan-dev/stan into feature/fix-csv-for-matrices

Conflicts:
	src/test/io/csv_writer_test.cpp
Merge pull request #183 from stan-dev/feature/fix-csv-for-matrices

Fixes #181.
Fix CSV output of matrices to be in column-major order