Improvements of "gf -server" mode and related setup

"gf -server" mode now contains everything needed to run the minibar and
the grammar editor (including example-based grammar writing).

The Setup.hs script installs the required files where gf -server can find them.
These files have been moved to a new directory: src/www.

The separate server program pgf-http is now obsolete.

src/www/gfse/grammars.cgi

@@ -0,0 +1,19 @@
+#!/bin/bash
+echo "Content-Type: text/javascript"
+echo ""
+
+case "$QUERY_STRING" in
+  jsonp=*) prefix="${QUERY_STRING#jsonp=}("; suffix=")" ;;
+  *) prefix=""; suffix=""
+esac
+
+echo -n "$prefix"
+sep="["
+for g in *.pgf ; do
+  echo -n "$sep\"$g\""
+  sep=", "
+done
+echo "]$suffix"
+#echo "/*"
+#set
+#echo "*/"