The former lvm dumpconfig originally used to simply dump existing configuration has evolved into an LVM command (lvmconfig) used to handle LVM configuration in general.

Add support for performing in-place edits in lvm.conf by using lvmconfig command (or simply generating the new config file, keeping existing settings and format from original config file and changing settings needed, then overwriting the original config - still needs a design decision). Hence, make it also possible to merge the functionality that is currently provided by lvmconf script. This script currently uses "sed" heavily to do the substitutions and all the editing. This should be all replaced by lvmconfig functionality in the end.