Native script SetGasp() extended to version 1 tables

@MichinariNukazawa [reported](https://mail.google.com/mail/u/0/#inbox/148ad5832ecbf196)
that they were not able to set values for TTF 'gasp' table.  It was
discovered that the native scripting function SetGasp() had not yet
been updated to support 'gasp' version 1 additional flags.

Matthew Skala [reported](https://mail.google.com/mail/u/0/#inbox/148af2d5160f1639)
he had [updated](https://github.com/mskala/Tsukurimashou/commit/c225dabd5dd5fda56358ece93755cf14be6e26ac)
FontAnvil to allow SetGasp() to apply version 1 flags.

Testing that change in FontForge revealed a small needed modification
(four bit flags gives upper limit for mask of 15, as seen in MS docs).

Tested before and after change, and @mskala 's change automatically sets
the table version number as needed, as there is no native scripting method
to do so.

Apple documents version 0 flags:
  https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6gasp.html
Microsoft documents version 1 flags:
  http://www.microsoft.com/typography/otspec/gasp.htm
Merge pull request #1753 from tshinnic/native_gasp_version_1_flags

Native script SetGasp() extended to version 1 tables