[MacPorts] #53847: scummvm update to 1.90, enable further features

[MacPorts]

#53847: scummvm update to 1.90, enable further features
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 Reporter:  kencu   |      Owner:
     Type:  update  |     Status:  new
 Priority:  Normal  |  Milestone:
Component:  ports   |    Version:
 Keywords:          |       Port:  scummvm
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 The old version 1.70 on mac ports is several years out of date. This diff
 updates to 1.90, and in the process I enabled as many of the enhancements
 as I could. Builds successfully on 10.6.8 (libc++/clang-3.8) and 10.12.3.

 After installing, run scummvm and in the settings, configure it for OpenGL
 to get the best screen images (IMHO).

 scummvm defaults to sdl2 now, so I switched the deps to libsdl2 and
 libsdl2_net as well. This required one small patch to find the proper
 libsdl2_net include file.

 To be noted that it is possible to build it against libsdl still, and on
 the scummvm website there are builds for old Macs (PPC even) that you can
 download. I didn't bother going through the exercise of configuring and
 testing a portfile  for those systems. On the other hand, this portfile
 allows building the current version 1.9.0 against libsdl2 on 10.6.8, which
 does not exist otherwise.

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Ticket URL: <https://trac.macports.org/ticket/53847>
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