Add sharing of groups between databases

* Add source folder keeshare for sharing with corresponding define WITH_XC_KEESHARE
* Move common crypto parts to src/crypto/ssh
* Extended OpenSSHKey
* Move filewatching to own file (currently in two related classes DelayedFileWatcher and BulkFileWatcher)
* Small improvements for style and code in several classes
* Sharing is secured using RSA-Keys which are generated on demand
* Publisher signs the container using their private key
* Client can verify the signed container and choose to decline an import,
import only once or trust the publisher and automatically import all
data of this source henceforth
* Integration of settings into Group-Settings, Database-Settings and Application-Settings
* Introduced dependency QuaZip as dependency to allow combined export of
key container and the (custom format) certificate

src/core/Tools.h

@@ -56,6 +56,33 @@ namespace Tools
         }
     }
 
+    template <typename Key, typename Value, void deleter(Value)> struct Map
+    {
+        QMap<Key, Value> values;
+        Value& operator[](const Key index)
+        {
+            return values[index];
+        }
+
+        ~Map()
+        {
+            for (Value m : values) {
+                deleter(m);
+            }
+        }
+    };
+
+    struct Buffer
+    {
+        unsigned char* raw;
+        size_t size;
+
+        Buffer();
+        ~Buffer();
+
+        void clear();
+        QByteArray content() const;
+    };
 } // namespace Tools
 
 #endif // KEEPASSX_TOOLS_H