enable predicate modification of index of value which is currently being added/removed

Todo: test if this works for removal ( I think it should ).

testing/btest/scripts/base/frameworks/input/predicatemodify.bro

@@ -0,0 +1,50 @@
+#
+# @TEST-EXEC: bro -b %INPUT >out
+# @TEST-EXEC: btest-diff out
+
+@TEST-START-FILE input.log
+#separator \x09
+#path	ssh
+#fields	i	b	s	ss
+#types	int	bool	string	string
+1	T	test1	idx1
+2	T	test2	idx2
+@TEST-END-FILE
+
+redef InputAscii::empty_field = "EMPTY";
+
+module A;
+
+type Idx: record {
+	i: int;
+	ss: string;
+};
+
+type Val: record {
+	b: bool;
+	s: string;
+};
+
+global servers: table[int, string] of Val = table();
+
+event bro_init()
+{
+	# first read in the old stuff into the table...
+	Input::add_table([$source="input.log", $name="input", $idx=Idx, $val=Val, $destination=servers, 
+				$pred(typ: Input::Event, left: Idx, right: Val) = { 
+				if ( left$i == 1 ) {
+					right$s = "testmodified";
+				} 
+
+				if ( left$i == 2 ) {
+					left$ss = "idxmodified";
+				} 
+				return T; 
+				}
+				]);
+	Input::remove("input");
+}
+
+event Input::update_finished(name: string, source: string) {
+	print servers;
+}