When saving warmup during optimization, also save the first sample.  Makes debugging easier.
Merge branch 'develop' of https://github.com/stan-dev/stan into feature/write-init-during-opt
Merge branch 'develop' into feature/write-init-during-opt

Conflicts:
	src/stan/gm/command.hpp
Implement saving the first sample during optimization in the new command.
Save the initial state during optimizaiton.
Merge branch 'feature/write-init-during-opt' of https://github.com/stan-dev/stan into feature/write-init-during-opt
Tweaked NUTS algorithm with correct behavior at each subtree
Added compute_criterion unit tests
Added built_tree unit tests
Remove deprecated cout
Merge branch 'develop' into feature/write-init-during-opt

Conflicts:
	src/stan/gm/command.hpp
Fix compilation error.
Merge branch 'feature/write-init-during-opt' of https://github.com/stan-dev/stan into feature/write-init-during-opt

Conflicts:
	src/stan/gm/command.hpp
Merge pull request #334 from stan-dev/hotfix/fix_nuts

Fixes #326.
Merge pull request #182 from stan-dev/feature/write-init-during-opt

Save the initialization state in the CSV file when doing optimization and saving warmup