Sqlite: Cleanup Sqlite

We don't need the threading anymore, so we removed it. The indexer
will be run in its thread anyway, so an extra thread makes the code
only more complicated. And we added namespaces.

Change-Id: Ibcba306324763285cf653c28bb08122345e5f8da
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/libs/sqlite/sqlitedatabasebackend.h

@@ -33,6 +33,8 @@
 
 struct sqlite3;
 
+namespace Sqlite {
+
 class SQLITE_EXPORT SqliteDatabaseBackend
 {
 public:
@@ -102,7 +104,9 @@ protected:
     Q_NORETURN static void throwException(const char *whatHasHappens);
 
 private:
-    sqlite3 *databaseHandle;
-    TextEncoding cachedTextEncoding;
+    sqlite3 *m_databaseHandle;
+    TextEncoding m_cachedTextEncoding;
 
 };
+
+} // namespace Sqlite