added implementation of mesh/coordset verify

added implementation of mesh verify that relies on:
 mesh/coordset (implemented)
 mesh/topology (unimplemented)
 mesh/field (unimplemented)

added info output to mcarray verify

wired generic interface for path based protocol identification

 ex:
  blueprint::verify(n,"mesh/coordset")
   maps to
  blueprint::mesh::coordset::verify(n,"mesh/coordset")

still evolving structure of the info output for verify, but
it looks like the following:

{
  valid = "true" or "false"
  (if errors)
      errors = ["error string 1", "error string 2"]

  child
  {
    valid = "true" or "false"
    (if errors)
        errors = ["error string 1", "error string 2"]
  }
  ...
}

this allows us to report errors at any part in a hierarchy, but
assumes protocols won't require the names "valid" or "errors"

also:
refactored verify logging logic + helpers
added check for grid_function to bp::mesh::generate_index

remove none info variants of verify funcs

refactor bp verify sub cases into actual protocols

added more structure to coord_system protocol to support
cart, cylnd, and spherical

…m/llnl/conduit into enh/2016_09_blueprint_mesh_verify