Fix infinite loop when rev mode implementation of gamma_p overflows
Merging into develop

Merge branch 'develop' of https://github.com/stan-dev/stan into develop
Merging branch
Merge branch 'develop' of https://github.com/stan-dev/stan into develop
Efficient implementation of multiply_lower_tri_self_transpose.hpp
Modified test file to include symmetry checks on large matrices
Merge branch 'develop' into bugfix/issue-1121-multivariate-error
updated test
Merging
Merge branch 'bugfix/issue-1121-multivariate-error' of https://github.com/stan-dev/stan into bugfix/issue-1121-multivariate-error
Removed old method from unit/math/matrix test, changed the large L matrix generator function, added the test to agrad/rev/matrix test, cleaned up commented code
update pdflatex options

- fixed typo in option interaction so that the manual compilation does not wait for user input.
- added option -file-line-error which allows emacs compile to pick out
  error messages
Merge pull request #1134 from stan-dev/bugfix/issue-1133-fix-pdflatex-options-in-make

update pdflatex options
Add environment stancode, put all Stan code in that environment
Merge branch 'develop' into feature/issue-674-overflow_gamma_p_derivative
Added comment describing asymptotic behavior
Merge pull request #1136 from stan-dev/feature/issue-1135-manual-stancode-environment

Add environment stancode, put all Stan code in that environment
fixed the definition of gamma_p
Merge pull request #1137 from stan-dev/feature/issue-674-overflow_gamma_p_derivative

Fixes #674. Feature/issue 674 overflow gamma p derivative
Merge branch 'develop' of github.com:stan-dev/stan into develop
small fix for beta distribution error messages
Added neg_binomial_2_cdf + tests