Makefile.am: remove references to doc/docbook/nmsg.ent, which was removed
nmsgtool.docbook: fix tab damage
nmsgtool.docbook: document -L and -S
my/m4/ax_compare_version.m4: new
Merge branch 'master' of ../libmy
m4/: enable AX_COMPARE_VERSION
README.md: add docbook-xsl to the recommended debian packages for building the documentation