Add support for ":0" indexing of nodes in graphdef

Sometimes the generated graph defs specify the 0'th output explicitly.
Example:
node {
  name: "abc"
  input: "Placeholder_1:0"
}
node {
  name: "Placeholder_1"
  op: "Placeholder"
}
Node abc specifies that it wants the 0th output of the Placeholder_1 node.
However in single output nodes, the tensor name is same as node name. So
Placeholder_1:0 tensor cannot be found. The same is also true for the 0th output
of multiple output nodes (output tensor names will be node_name,node_name:1,..)

So while parsing the graph def we strip away any ":0" from the input names.

Athos/TFCompiler/Graph.py

@@ -579,7 +579,12 @@ class Node:
                 self.__op = tokens[1][1:-1]
             elif (curToken == "input:"):
                 if (errIfTokensNotMinLen(tokens, 2, cnt, "node")): return (False, cnt)
-                self.__inputs.append(tokens[1][1:-1])
+                input_name = tokens[1][1:-1]
+                # Sometimes graph defs generated specify 0'th output explicitly whereas the node names do not
+                # contain that. So we strip it
+                if input_name.endswith(":0"):
+                    input_name = input_name[:-2]
+                self.__inputs.append(input_name)
             elif (curToken == "attr"):
                 (noParseError, cnt) = self.readAttrFromFilePointer(fileP, cnt)
                 if (not(noParseError)):