Since Meson 0.44, subproject_dir may not be '.' anymore. This implies we
must move app/ and server/ to a subprojects/ directory, which requires
to also change some gradle files.
Instead, just use subdir(), with options to disable building of the app
or the server.
The client was built with Meson, the server with Gradle, and were run by
a Makefile.
Add a Meson script for the server (which delegates to Gradle), and a
parent script to build and install both the client and the server to the
system, typically with:
meson --buildtype release build
cd build
ninja
sudo ninja install
In addition, use a separate Makefile to build a "portable" version of
the application (where the client expects the server to be in the
current directory). Typically:
make release-portable
cd dist/scrcpy
./scrcpy
This is especially useful for Windows builds, which are not "installed".
