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.
util-lib: use MODE_INVALID as invalid value for mode_t everywhere
util-lib: split out allocation calls into alloc-util.[ch]
user-util: move UID/GID related macros from macro.h to user-util.h
util-lib: move a number of fs operations into fs-util.[ch]
util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.
util: rework rm_rf() logic - Move to its own file rm-rf.c - Change parameters into a single flags parameter - Remove "honour sticky" logic, it's unused these days
util: rework strappenda(), and rename it strjoina() After all it is now much more like strjoin() than strappend(). At the same time, add support for NULL sentinels, even if they are normally not necessary.
treewide: convert some left-over (usec_t) -1 to USEC_INFINITY
treewide: introduce UID_INVALID (and friends) as macro for (uid_t) -1
test: ensure conf_files_list returns absolute paths