Issue 3015 - store timestamp when password is reset (#3863)

* Added few unsigned to ints in order to get rid of warnings.
Added column to users table, for when password is changed(issue#3015).
Moved password length check to separate method, to make it cleaner.
* Added migration file and changed schema version to 27 due to servatrice.sql schema modification.
* Make password length configurable.

servatrice/src/serversocketinterface.h

@@ -122,6 +122,8 @@ private:
     bool addAdminFlagToUser(const QString &user, int flag);
     bool removeAdminFlagFromUser(const QString &user, int flag);
 
+    bool isPasswordLongEnough(const int passwordLength);
+
 public:
     AbstractServerSocketInterface(Servatrice *_server,
                                   Servatrice_DatabaseInterface *_databaseInterface,