GSOC Build tests

[Greg Williamson]

So over the week I started writing continuous integration build tests for several platforms. You can preview them here:

https://dev.azure.com/fundies/freetype2/_build/results?buildId=146&view=results

Builds are uploaded here:

https://dev.azure.com/fundies/freetype2/_build/results?buildId=146&view=artifacts&type=publishedArtifacts

Please let me know if there are any additional compilers, operating systems or configurations you would like tested. Also, if you would like any other build system tested other than cmake tested. I would also like to test freetype-demos but I'm not sure if those are only valid on desktop configurations.

I did have some issues with Mac/iOS builds as your repo seems to have an iOS.cmake that is 6 years old and incompatible with modern xcode and I had so set a blank signing key for OS X. I found a newer iOS.cmake to replace your current one and it seems to work however it does not currently bundle the binaries in the packaging stage. Please let me know if you have better solution for either of these.

Lastly, I'm not familiar with how to commit to your repo I only get "fatal: remote error: access denied or repository not exported: /freetype/freetype2.git" without ever being prompted for a login. So instead here is a patch: https://github.com/fundies/freetype2/commit/564f8d163fbed71cccd1a9ea5733e28da82b7d7e.patch