Clang: Minimize reindexing

We optimal indexer is only reindexing if the index would be changed. This
patch is a step in that direction. We only reindex now if the file or
project has changed. It fixes some typos too.

Task-number: QTCREATORBUG-21150
Change-Id: I6ea1c13282fbcd70253b9b2939aed37580dbd160
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/libs/clangsupport/refactoringdatabaseinitializer.h

@@ -177,6 +177,7 @@ public:
                         Sqlite::Contraint::PrimaryKey);
         table.addColumn("size", Sqlite::ColumnType::Integer);
         table.addColumn("lastModified", Sqlite::ColumnType::Integer);
+        table.addColumn("indexingTimeStamp", Sqlite::ColumnType::Integer);
         table.initialize(database);
     }
 
@@ -188,6 +189,7 @@ public:
         const Sqlite::Column &sourceIdColumn = table.addColumn("sourceId", Sqlite::ColumnType::Integer);
         const Sqlite::Column &dependencySourceIdColumn = table.addColumn("dependencySourceId", Sqlite::ColumnType::Integer);
         table.addIndex({sourceIdColumn, dependencySourceIdColumn});
+        table.addIndex({dependencySourceIdColumn, sourceIdColumn});
 
         table.initialize(database);
     }