updating argument configuration test to not generate 'good' and 'samples.csv' in the working directory
updating test/gm/command to not leave any files in the working directory
broke apart src/stan/command/print.cpp to the main and functions. added unit tests for next_index and matrix_index. made those two functions safer.
updating cmd_line to allow for spaces in string arguments
Merge branch 'develop' into feature/issue-185-command-line-handle-spaces
Merge branch 'develop' into feature/issue-280-bin-print-blowing-out-memory
Merge pull request #311 from stan-dev/feature/issue-310-test-unit-littering

Fixes #310.
Merge pull request #328 from stan-dev/feature/issue-185-command-line-handle-spaces

Fix to stan::io::cmd_line to allow spaces in string arguments
Merge pull request #327 from stan-dev/feature/issue-280-bin-print-blowing-out-memory

Fixed unsafe code in bin/print
Merge branch 'develop' of https://github.com/stan-dev/stan into feature/parser_error_reporting