Merge branch 'develop' of https://github.com/stan-dev/stan into develop
added raise_exception, compiles, tested by hand
added models for integration test
added tests for functions which throw exceptions
switched order of error checks, made error messages more consistent, updated unit test
cleanup - code for raise_exception stmts should be in branch issue-748, not in this one.
stan models that test error detection, error message
cleanup - wrong branch for these test models
Added cbind functions and tests
Added rbind functions and tests
Extra test to cbind and rbind
cbind: functions with correct promotion of args and added agrad-rev tests
rbind: functions with correct promotion of args and added agrad-rev tests
Some basic fwd-rev tests for cbind and rbind
Added cbind and rbind to function signatures and related signature tests
Minor improments to rbind and cbind
Fix incorrect reference to inverse in to_matrix function signature test
Added documentation for cbind and rbind + minor fix for Transposition Postfix Operator documentation
split out parser_test
Fixed typo in rbind documentation as was pointed out by Peter Li