This alters the build setup to create two executables based on
practically the same CPP static lib but with different QML
dirs and translations.
This also adds a cmake option
-Dlocal_qml=ON
when passed it will create an executable that will load the QML
from local disk instead of using the compiled-in version.
The main advantage of that is that there is no need to recompile
after each QML change.
The english ts file is not packaged as it would be a no-op file
anyway, but we generate it because it is used for uploading to our
translations platform.
Similarly we ignore the file since it should not be in git, again
because it contains only the source strings.
tomFlowee