Added Welford estimation classes

Factored adaptation algorithms from wrapper

Removed deprecated tests, added new ones

Fixed typo in include paths

Upated adaptation algorithm tests

Type in test vector initialization

Added Welford estimator tests

Adaptation refactor
Merge branch 'master' of github.com:stan-dev/stan

Merge adaptation refactor
rstan: calculation of number of saved draws differently due to the merge of hmc_refactor
rstan, change due to 27aea6753d26789e57df2484d891ccc39fa1f065
Better guessing of initial step-size with BFGS.
new to-do items for vector slicing and matrix flattening
new accessor functions in model, partway done
added error messages for sampling anything other than a parameter
updating model command test
fixed generator to not redeclare param_name_stream__
Jeffrey Oldham patches for unspecified picky compiler [some virtual declarations and warning suppression pragmas]
Merge branch 'master' of https://github.com/stan-dev/stan
added operator/ and operator\ for matrix matrix
Fix memory leak-like behaviour when exceptions are thrown from prog_agrad_ad model.
Add sub_column and sub_row functions.
Rename sub_column to sub_col to be consistent with other Stan functions.
rstan: add try/catch for parameter initalization
more to-do items around error checking initializations
more acknowledgments for patches in manual
fixed type inference problem for int with multiply; need to do elsewhere