[libqglviewer] add new port

[TheScarfix]

Adding a new portfile for the QGLViewer library http://libqglviewer.com/

[Rastaban]

@TheScarfix I see failures in the static windows builds, are these expected?

[TheScarfix]

http://libqglviewer.com/installWindows.html I think it is dll only
on windows, also haven't tested the other platforms yet

[Rastaban]

Our CI system avoids building ports that are unchanged by caching the installed files. qt5-base is doing something that causes it to not be cached correctly in our system which can cause failures in dependent ports that should build correctly. I am looking into addressing that issue but it should not hold up this PR. To work around the issue I made a whitespace change in qt5-base which should get the system to do a clean build. I should be able to merge this change after that completes.

[TheScarfix]

@Rastaban thank you :) will work on a linux compatible version as soon as I get the qmake system working there.

[Rastaban]

NP, thanks for the work! The tests looks better with the qt5-base rebuild so I am going to accept this port as is, when you get the Linux compatible version it can be added in a separate PR.