Move header extraction to python script and improve compatibility.

headerextract.py

@@ -0,0 +1,22 @@
+import sys
+
+#inFile = sys.stdin
+
+beginSig = "-----BEGIN PGP"
+endSig = "-----END PGP"
+output = ""
+keyBegun = False
+
+for line in sys.stdin:
+	sigIndex = 0
+	if beginSig in line:
+		if keyBegun:
+			exit(1)
+		keyBegun = True
+		sigIndex = line.find(beginSig)
+	if keyBegun:
+		output += line[sigIndex:]
+	if endSig in line:
+		break
+
+print(output)