Verify privKey of groupID when creating new group
Names and Messages are now added in textContent instead of innerHTML to prevent HTML injection
Both direct message and group message use the same IDB objectStore
Converted send message input to textarea : now users can send multi-line messages
Minor UI changes and fixes
Improved Enter Key Press :
Shift+Enter key will now insert a new line
(Enter key pressed without shift key will send message as before)
Enter key event to send message will now tigger on keydown instead of keyup
Added custom checkbox list for selecting users in group options
Added buttons to invoke group options
Hover on the 'more-options' (3-dot) button in the top-right corner to view group options
Note : group options will only be displayed when user is either creator or admin of respective group
