Enable SQLiteDB backend.

Multiple fixed and finished the implementation of the SQLite backend.
Try to load the database before trying to attempt a rescan.
Delete the metadala list for backends that allocate them on demand.
Moved some generic functions to the databse class.
Renamed utils header to avoid rare QtCreator bug.

src/cmautils.h

@@ -0,0 +1,53 @@
+/*
+ *  QCMA: Cross-platform content manager assistant for the PS Vita
+ *
+ *  Copyright (C) 2013  Codestation
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef UTILS_H
+#define UTILS_H
+
+#include <QByteArray>
+#include <QString>
+#include <QThread>
+
+#include <vitamtp.h>
+
+// Qt4 doesn't have public methods for Thread::*sleep
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+typedef QThread Sleeper;
+#else
+class Sleeper : QThread
+{
+public:
+    static void sleep(unsigned long secs) {
+        QThread::sleep(secs);
+    }
+    static void msleep(unsigned long msecs) {
+        QThread::msleep(msecs);
+    }
+    static void usleep(unsigned long usecs) {
+        QThread::usleep(usecs);
+    }
+};
+#endif
+
+bool removeRecursively(const QString &path);
+QString readable_size(qint64 size, bool use_gib = false);
+bool getDiskSpace(const QString &dir, quint64 *free, quint64 *total);
+QByteArray getThumbnail(const QString &path, DataType type, metadata_t *metadata);
+
+#endif // UTILS_H