Used Ajax in all JSP pages to Send Friend Request without reloading page.

1)- used Ajax's XMLHttpRequest to call Controller,s POST() which returns DTO object annoted with XML annotation like @XmlRootElement.
2)- In Controller's Post method at this time we are not Fetching data Again.
3)- We Just inserting Data in to 'friend_request' Table using POST() of Controller Class.
4)- Fetching Data only in get() method of Controller Class.
5)- Also added '.png' in Request Intersepter.
6)- At Service Layer getting 'Loged_In_User_Mail' from session.
7)- Changed Background Image through CSS.

Signed-off-by: manojsa <sawantmanojm@gmail.com>