Merge #12: Bind get_wch and form_driver_w

form_driver_w is included in Ncurses 5.9-20131207 [0]. An example
program is provided in examples/form_get_wch.rb.

[0] http://lists.gnu.org/archive/html/bug-ncurses/2013-12/msg00010.html

Squashed commit of the following:

commit d077f467996c1f3e2bf19fda8d30419283700cd4
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Mon Dec 2 11:58:50 2013 +0100

    use driver_w for class method

commit 20e4d711258fcbc25ad3283c98e40dbae7c65045
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Mon Dec 2 10:53:26 2013 +0100

    dont define USE_WIDEC_SUPPORT

commit 1f67d1d78fffaba8a652dde318a760e0de75393e
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Mon Nov 25 12:49:49 2013 +0100

    copyright me and fix ws

commit b1244701a3ad96bead0dcaf0d26b484284f1365d
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Sat Nov 23 15:56:59 2013 +0100

    Wrap form_driver_w

commit ddd52161a44537ddb0809cbdced648eb45afaff2
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Sat Nov 23 15:51:27 2013 +0100

    wrap form_driver_w

commit d4e1590e0035c5cbb2143c8941d6cd79c958bd62
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Fri Nov 22 13:55:08 2013 +0100

    WIP: add_wch

commit 42b36f751fdaad30a6517397e11068dfa8accc5b
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Wed Nov 20 10:15:35 2013 +0100

    Use Ncurses constants

commit aaf53e52c07e744341537d65afbec55fc360b973
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Wed Nov 20 10:03:06 2013 +0100

    pack as unicode char

commit 4481f31042cc379a026c68fbfb3919c6930c673a
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Wed Nov 20 07:20:15 2013 +0100

    check for formw, return long

commit 25ade76617c2145da9f0972704be2184343e77d7
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Wed Nov 20 00:01:06 2013 +0100

    return array with return type and ruby string

commit 5475417b0861d2c1867ef3ecb19f0cdbc8b2828c
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Tue Nov 19 18:33:29 2013 +0100

    Actually use wget_wch, wrap in function of same type as wgetch

commit cbc259754da2aa27fa1655f57e6ead6c6fa44eeb
Author: Gaute Hope <eg@gaute.vetsj.com>
Date:   Tue Nov 19 17:51:47 2013 +0100

    bind get_wch for wide char input