ATS2-0.2.2

## ats2-postiats-0.2.2:

    This is the 25th release of ATS2, the successor of the ATS
    (currently referred to as ATS1) programming language. The compiler
    for ATS2 is given the name ATS/Positats, ATS2/Postiats or simply
    Postiats.

    The official website for ATS is:

    http://www.ats-lang.org

    ATS-Postiats is hosted at github:

    https://github.com/githwxi/ATS-Postiats

    Major releases of ATS2 are available at:

    https://sourceforge.net/projects/ats2-lang/

    Major releases of external packages for ATS2 are available at:

    https://sourceforge.net/projects/ats2-lang-contrib/

    Here is a list of major additions and changes since the last release:

    1. Adding support for explicitly boxed types: boxed and boxed_vt
    2. Adding backup links to INT2PROGINATS, ATS2TUTORIAL, and EFFECTIVATS.
    3. Fixing a bug in typechecking loop invariants (see bug-2015-08-04).
    4. Adding [g0int_npow] and [g0float_npow] and overloading ** with them.
       For instance: (x+y)**3 expands to x**3 + 3*x**2*y + 3*x*y**2 + y**3
    5. Adding the_s2rtdatmap to the jsonization of generated constraints
       (for listing the inductively defined sorts used in the constraints)
    6. Supporting tail-call optimization for static function templates
    7. Supporting #codegen2 for datcon, datcontag, and fprint
    8. Supporting the use of $d2ctype for taking the type of a dynamic constant