doc/manual.txt: multiple improvements and tweaks.
xbps-src: bump version (v90).
common/global-defs.sh: require xbps-src >= 90.
Update all source packages for xbps-src>=90.
lxappearance: update to 0.5.4.
automake: update to 1.14.1.
gdbm: update to 1.11.
automake: fix run-time deps (tyop).
gdbm: require a working automake to fix the build.
minicom: update to 2.7.
doc/manual.txt: update for xbps-src>=90.
shorewall: update for xbps-src>=90.
dvtm: update to 0.10