Bug 903245 : Support sharing of Contact via NFC; r=reviews.

1. To make vCard using ContactToVcard() function in contact2vcard.js
2. Addition/Removal of NfcPeerHandler method in Contact.js and details.js  respectively
3. Various Test condition includes (mozNfc support, Valid Payload data, NDEF transfer status)
4. VCARD 4.0 Version Not Supported and NFC KEY ID Should be Upper Case (N,FN,BDAY,ADR,EMAIL). I changed into 2.1 VERSION.
5. setImmediate is not supporting now,Removed.
6. Tested against Nexus-4  & Samsung S4 Android device