End-to-end encryption UI/UX

#723

- Display device information when user taps on the encryption icon.
- Add this option in event context menu

Vector/Views/EncryptionInfoView/EncryptionInfoView.h

@@ -0,0 +1,29 @@
+/*
+ Copyright 2016 OpenMarket Ltd
+ 
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+ 
+ http://www.apache.org/licenses/LICENSE-2.0
+ 
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <MatrixKit/MatrixKit.h>
+
+@interface EncryptionInfoView : UIView
+
+@property (weak, nonatomic) IBOutlet UITextView *textView;
+@property (weak, nonatomic) IBOutlet UIButton *okButton;
+@property (weak, nonatomic) IBOutlet UIButton *verifyButton;
+@property (weak, nonatomic) IBOutlet UIButton *blockButton;
+
+- (instancetype)initWithEvent:(MXEvent*)event andMatrixSession:(MXSession*)session;
+
+@end
+