[ci] Setup CI build with sourcehut
Disable deprecated gtkmm-2.4 API, add CFLAGS required for gtkmm
Remove use of deprecated gtkmm-2.4 API, require gtkmm-2.4 ≥ 2.18
Remove redundant copy constructor
Upgrade CMake via brew in macOS Travis build.
Clearer naming for build system switching.
Require CMake >= 3.12, install cmake via brew in macOS Travis build.
Install librsvg before macOS build.
Rename RSVG variable to fix Travis CI build.
Install rsvg-convert tool in Travis build.
Explicitly specify destination for application binary.
Use CMake in Travis build as well.
Install SCons on Travis-CI/Linux.
Add files to support building with CMake.
sonar-scanner doesn't seem to be working with SCons.
Add sonar-project.properties for sonarcloud
Enable sonarcloud code scanning
Add image linking to current build status.