Convert makefile to shell commands in appveyor config, various other tweaks

dist_assets/linux/AppRun

@@ -0,0 +1,19 @@
+#! /bin/bash -i
+
+# Export APPRUN if running from an extracted image
+self="$(readlink -f -- $0)"
+here="${self%/*}"
+APPDIR="${APPDIR:-${here}}"
+
+# Export TCl/Tk
+export TCL_LIBRARY="${APPDIR}/usr/share/tcltk/tcl8.4"
+export TK_LIBRARY="${APPDIR}/usr/share/tcltk/tk8.4"
+export TKPATH="${TK_LIBRARY}"
+
+# Export SSL certificate
+export SSL_CERT_FILE="${APPDIR}/opt/_internal/certs.pem"
+
+# Call the entry point
+#! /bin/bash -i
+
+${APPDIR}/usr/bin/pyfa "$@"