Refactor config file parsing and improve error handling

Change-Id: I8a54ba1f0d414bea70923e0f45ca354ac7e957a3
diff --git a/ndn-traffic-server.conf.sample b/ndn-traffic-server.conf.sample
index 7c8b540..aadc9eb 100644
--- a/ndn-traffic-server.conf.sample
+++ b/ndn-traffic-server.conf.sample
@@ -3,26 +3,25 @@
 #
 # * TO BE USED TO CONFIGURE RESPONSE TO INTERESTS
 # * MULTIPLE SERVER PREFIXES CAN BE CONFIGURED FOR BEING HANDLED
-# * EVERY INIVIDUAL PATTERN DESCRIPTION MUST BE SEPARATED BY ONE
+# * EVERY INDIVIDUAL PATTERN DESCRIPTION MUST BE SEPARATED BY ONE
 #   OR MORE '#' CHARACTERS FOR THE TOOL TO DISTINGUISH THEM
-#   INDIVIDUALLY
 # * THE FOLLOWING PARAMETERS MAY BE ADDED FOR EVERY TRAFFIC PATTERN
-# * (Mandatory) NEXT TO A PARAMETER MEANS EVERY PATTERN SHOULD HAVE
-#   IT FOR BEING CONSIDERED VALID
-#   (Optional) MEANS OTHERWISE
-# * ALSO PROVIDED ARE VALID VALUES POSSIBLE FOR EACH PARAMETER
-# * NNI STANDS FOR NON-NEGATIVE INTEGER
+# * 'Mandatory' ARE PARAMETERS THAT EVERY PATTERN MUST HAVE IN ORDER
+#   TO BE CONSIDERED VALID
+# * 'Boolean' ACCEPTS EITHER 0/false/no/off OR 1/true/yes/on AS VALUE
+# * 'NNI' STANDS FOR NON-NEGATIVE INTEGER
 # * RANGE OF POSSIBLE VALUES IS SPECIFIED IN []
 #
+
 # (Mandatory)
 #Name=NDN Name
 #
 # (Optional)
+#ContentDelay=Milliseconds [>=0]
+#FreshnessPeriod=Milliseconds [>=0]
 #ContentType=NNI [>=0]
-#FreshnessPeriod=NNI [milliseconds]
 #ContentBytes=NNI [>0]
 #Content=String
-#ContentDelay=NNI [milliseconds]
 #SigningInfo=String [examples below]
 
 ##########