configure.ac: improve shell compatibility, generate package version components at autoconf time
configure.ac: improve shell compatibility, generate package version components at autoconf time

git-svn-id: d3d46767b8f15aa15dc28b4413db96165ce057f7@38033 140774ce-b5e7-0310-ab8b-a85725594a96

svn2github/libmicrohttpd,svn2github/libmicrohttpd,svn2github/libmicrohttpd,svn2github/libmicrohttpd