We'd always get "0x0: something" where the 0x0 is the xcb_window which
obviously doesn't translate.
Instead show the class name so we can easily track what kind of object
we are dealing with.
It's an easy way to show which shell it's using on Wayland, will be
useful in other cases as well.
Once in a while, we receive complaints from other fellow KDE developers
about the file organization of kwin. This change addresses some of those
complaints by moving all of source code in a separate directory, src/,
thus making the project structure more traditional. Things such as tests
are kept in their own toplevel directories.
This change may wreak havoc on merge requests that add new files to kwin,
but if a patch modifies an already existing file, git should be smart
enough to figure out that the file has been relocated.
We may potentially split the src/ directory further to make navigating
the source code easier, but hopefully this is good enough already.
