Fix : In reference to Issue #105 : File input with the --data flag doesn't work

• In ProcessData function, if the --data flag is passed with a filename only, it is not included in the data. The file (@fiLENAme) is included only when a key is passed. ie.,

   --data "content=@some.json"  // This is processed.

  And when the --data flag is passed with just the filename without a key, like :

   --data "@some.json" // This is ignored.

  Thus adding functionality to read the file in case the key is not given.
• Header parsing : Header is added only when a particuar format is followed : "Key: Value". But curl also accepts "Key:Value" (without the space near the colon". Modified setHeaders function to follow curl's standards