[Ohrrpgce] SVN: teeemcee/8289 Add palette16_duplicate.

[subversion at HamsterRepublic.com]

teeemcee
2016-12-31 05:11:16 -0800 (Sat, 31 Dec 2016)
217
Add palette16_duplicate.

I would have added palette16_{duplicate,assign} too, however that
wouldn't make sense, because Frame and Palette16 refcounts work
differently: palette16_new returns a non-refcounted Palette16
---
U   wip/allmodex.bas
U   wip/allmodex.bi
U   wip/udts.bi