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: 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.

dhcp-identifier: fix for unaligned write Reported by Michael Olbrich.

remove unused includes This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.

Add missing includes in header files This fixes various issues found by globally reordering the include sections of all .c files.

network: dhcp - split out dhcp_identifier_set_{iaid,duid_en} from dhcp6-client This will also be used in dhcp4-client.

network: dhcp - split out the duid structure into a new header file We will use the same in both dhcp4 and dhcp6.