Remove the logo step, and use PrintStep for the header step.
The logo step was added as a quick fix after the Builder.addLog function
was removed.
Now the logo is no longer shown when running `zig build -l` or
`zig build -h`.
The version check for Zig 0.6.0 was incorrect since commit
971ab7f (Use a zig build script to run ziglings).
Move compatibility support to a separate file, in order to simplify
build.zig.
In case of incompatible version, exit with code 3 instead of 0, in order
to detect the case of failure in a test (to be implemented).
Remove the use of comptime when checking compatibility at the start of
the build function, since it is not necessary.
Closes#210.
Currently, the logo is always printed when the build script is executed,
resulting in the logo being printed twice with `zig build -h` and
`zig build -l`.
Make the logo a build step, so that the logo is printed to stderr only
when necessary.
Closes#211
Manlio Perillo