Resolves: #i124179# trigger update User Fields...

and related Input Fields when user directly edits a User Field Input Field

- assure that no recursive updates occur

(cherry picked from commit 3c2b5242e81575ec4b6c110afd88894670bd2283)

Conflicts:
	sw/inc/txtfld.hxx
	sw/source/core/fields/expfld.cxx
	sw/source/core/fields/usrfld.cxx

Change-Id: I36af4d5e8008f16737e3ec14c1ec737a5f43d3b1
(cherry picked from commit 50f0bb85b7e18001886fdf8bb03eb1d138838b90)