Silent build rules by default

Use make V=1 for the verbose mode (as used before)
pkcs15-profile.xml: remove empty SYNOPSIS section
Merge remote branch 'upstream/staging'
piv-tool.xml: fix typo
doc/tools/*.xml: use <refsynopsisdiv> sections

Use <refsynopsisdiv> sections with <cmdsynopsis> tags for the synopsis
instead of plain <refsectX> sections. Create one where it was massing.
doc/tools/*.xml: harmonize & complete <refmeta> sections
doc/tools/*.xml: use <citerefentry> in "See also" sections

Instead of using plain text, use machine-parsable <citerefentry> sections
to refer to other odcuments.
doc/tools/*.xml: add <refmiscinfo> class attributes

Use <refmiscinfo> with the class attributei values "productname","manual" and
"source".
This avoids some warnings when generating the manual pages.
doc/Makefile.am: get rid of "api.work" kludge
doc/tools/*.xml: include manpage sections in file names

Rename source XML files so that their names contain the manpage sections.
doc/tools/Makefile.am: new Makefile template for autotools

Created doc/tools/Makefile.am in order to generate a Makefile in doc/tools/.
Use pattern rules in doc/tools/Makefile.am; clean up doc/Makefile.am.
doc/tools/Makefile.am: substitute @pkgdatadir@
doc/tools/*.xml: more consistent formatting

uUse specific tags:
<command> for commands
<option> for options
<replaceable> for values that need to be replaced with real values
tools.xml: use 2 reference sections: tools & file formats

Split the contents into two reference sections:
on for tools and one for file formats.
opensc-explorer.1.xml: fix typos, more harmonization
piv-tool.1.xml: more harmonization, slight re-wording
pkcs15-crypt.1.xml: sort options alphabetically
opensc-explorer.1.xml: sort options & commands alphabetically
westcos-tool.1.xml: slight rewording
cardos-tool.1.xml: sort options alphabetically