maint: update file .hgignore
mapshow.m: return figure handle as stated in Texinfo file header; fix typö.
Added tag release-2.7.2 for changeset 6a449b8e3c88
update docs for release 2.7.2
doc/Makefile: adapt to Qt6 qhelpgenerator
NEWS: announce UNO improvements
NEWS, DESCRIPTION: prepare for release 2.7.2
NEWS, DESCRIPTION: prepare for 2.7.2 release.