Merge pull request #483 in G/fastr from...

Merge pull request #483 in G/fastr from ~STEPAN.SINDELAR_ORACLE.COM/fastr:feature/various-fixes to master

* commit 'fd8a7c91':
  Regenerate tests expected output
  Missing node sets the visibility
  Cat refuses non-zero length lists, expressions and language (like in GnuR)
  Binary comparisons support language objects
  Identical checks the types are the same
  Sprintf: when any arg is NULL return character(0)
  Eval supports numeric envir argument
  det_ge_real NA handling matches GnuR
  sort can handle na.last argument == NA
  Log copies attributes to the result
  Fix string2intNoCheck to allow leading zeros
  Deparse supports KEEPINTEGER