Add API remaining limit info when exception happens

There are two commits in this pull requests:
1. fb7c740 : Add API remaining limit info when exception happens. 
For example when we are trying to obtain user info from a private user, Instagram API will return with a 400 HTTP response and jInstagram converts this into an exception. In this case, API limit information changes and the existing jInstagram exceptions do not have this info.
To achieve this feature, I create a new interface ```org.jinstagram.InstagramResponse.java``` that contains API to retrieve the remaining API limit and let ```InstagramException``` implements this interface.
2. d3ff5cd : I encounter a case where ```meta``` property in ```InstagramErrorResponse``` is null. Below is the stack trace that I have. Therefore, I add a simple check for null value in ```meta```.
```
java.lang.NullPointerException: null
	at org.jinstagram.entity.common.InstagramErrorResponse.throwException(InstagramErrorResponse.java:31) 
	at org.jinstagram.Instagram.handleInstagramError(Instagram.java:802) 
	at org.jinstagram.Instagram.createInstagramObject(Instagram.java:792) 
	at org.jinstagram.Instagram.getRecentMediaFeed(Instagram.java:213)
```