[0.4.x] libvisual + libvisual-plugins: `configure.ac`: Be more helpful in absence of autoconf-archive and/or `pkg.m4`#371

hartwork merged 2 commits into0.4.xLibvisual/libvisual:0.4.xfrom

0.4.x-m4-pattern-forbidLibvisual/libvisual:0.4.x-m4-pattern-forbidCopy head branch name to clipboard