First solution to provide a multi-step resolution of a Tcl interpreter in our shell wrappers. Uses some bash scripting to walk a list of candidates: 1) interp in build directory, 2) intep in install directory, 3) tcl interp in PATH. Where appropriate (cases 2 & 3), restricts search to a specific tinterp version. By relying on a generic shebang line (/bin/sh) we do not run into package-dependency restrictions on Debian. So a win-win?
build system: - don't call genstubs from configure, since Debian does not seem to have genstubs.tcl installed. Now, we pre-generate the stub files for tcl8.5 and tcl8.6 and copy the "right" version depending on the configured version.