Fix filenames starting with capital letters.

I accidentally committed two new files with filenames starting
with capital letters from Windows machine. The Linux build
breakage was fixed by fixing the include lines. But the correct
fix is to fix filenames as we are using all lower letter filenames
in this project.

gui/filelist.cpp

@@ -19,7 +19,7 @@
 #include <QDir>
 #include <QFileInfo>
 #include <QDebug>
-#include "FileList.h"
+#include "filelist.h"
 
 QStringList FileList::GetDefaultFilters()
 {

gui/mainwindow.cpp

@@ -34,7 +34,7 @@
 #include "project.h"
 #include "report.h"
 #include "logview.h"
-#include "FileList.h"
+#include "filelist.h"
 
 // HTMLHelp is only available in Windows
 #ifdef WIN32