Refactor initialization routine assuming context_factory pattern is valid
Merge branch 'develop' into feature/issue-405-refactor-init
updating initialize_state to take an instantiated factory
changed initialize_state to a boolean function
removing non-standard error code
Merge branch 'develop' into feature/issue-405-refactor-init
adding comment to context_factory
updating test for context_factory
added doc and test for src/stan/common/initialize_state
initialize_state: broke out 0 case
initialize_state: broke out random initialization
using initialize_state_random function
added function for initialize_state_source
updated initialize_state to use initialize_state_source
added NaN test for check_greater_or_equal
added doc in code for check_greater_or_equal
added NaN test for check_column_index
added doc in code for check_column_index
added NaN test for check_matching_dims
added doc in code for check_matching_dims