Merge pull request #269 in G/fastr from...

Merge pull request #269 in G/fastr from ~ADAM.WELC_ORACLE.COM/fastr:feature/builtins_sprint to master

* commit '449f5f89': (28 commits)
  Partially reverted previous rewrite of parameter casts for readdDCF builtin.
  Rewritten parameter casts and fixed problems related to NA handling for the family of rep functions.
  Simplified parameter cast for make.unique builtin.
  Rewritten parameter casts for mapply bulitin.
  Rewritten parameter casts for readRenviron builtin.
  Rewritten parameter casts for readline builtin.
  Rewritten parameter casts for readDCF builtin.
  Rewritten parameter casts for getOption builtin.
  Rewritten parameter casts for on.exit builtin.
  Rewritten parameter casts for make.unique builtin.
  Added error messages.
  Added default values to findFirst method.
  Rewritten parameter casts for make.names builtin.
  enable passing tests
  work on as.vector
  deprecate some methods in CastBuilder that are dangerous
  fix complex formatting (zprecr function)
  enable passing tests
  work on Paste
  report work in "order"
  ...