[Contact] fix bug on addBatch function()

* the root cause is that attribute of contact in parameter is not
  set.
[Contact] fix bug on removeGroup() function

* the root cause of is that splice function() used wrongly.
[ContactRef] fix bug: ContactRef constructor logic issue
[ContactRef] fix bug: ContactRef intanceOf function
[ContactBase] fix bug on convertToString()

* A string should be returned by default
* check whether format is VCARD_30
Merge pull request #251 from xuzhang/dev

fix bug TDIS-5812