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.

shared: include what we use The next step of a general cleanup of our includes. This one mostly adds missing includes but there are a few removals as well.

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

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: introduce common version() implementation and use it everywhere This also allows us to drop build.h from a ton of files, hence do so. Since we touched the #includes of those files, let's order them properly according to CODING_STYLE.

tree-wide: fix write_string_file() user that should not create files The latest consolidation cleanup of write_string_file() revealed some users of that helper which should have used write_string_file_no_create() in the past but didn't. Basically, all existing users that write to files in /sys and /proc should not expect to write to a file which is not yet existant.

fileio: consolidate write_string_file*() Merge write_string_file(), write_string_file_no_create() and write_string_file_atomic() into write_string_file() and provide a flags mask that allows combinations of atomic writing, newline appending and automatic file creation. Change all users accordingly.

sysctl: minor simplifications

sysctl: move property handling to shared/