tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

basic,bus-error: return negative error from errno_from_name errno_from_name used an unusual return convention where 0 meant "not found". This tripped up config_parse_syscall_errno(), which would treat that as success. Return -EINVAL instead, and adjust bus_error_name_to_errno() for the new convention. Also remove a goto which was used as a simple if and clean up surroudning code a bit.

basic: include only what we use This is a cleaned up result of running iwyu but without forward declarations on src/basic.

tree-wide: sort includes Sort the includes accoding to the new coding style.

build-sys: split internal basic/ library from shared/ basic/ can be used by everything cannot use anything outside of basic/ libsystemd/ can use basic/ cannot use shared/ shared/ can use libsystemd/