Actors and genre edit

Implemented widgets for actor and genre editing of movies. Created new
MappingTableWidget for both genres and actors and revamped
ArchiveTreeView to show 2 widgets below the FilesTreeView separated by a
splitter.

While testing the new setup several bugs were fixed:
-an SQL syntax error in FilesTreeModel
-fixed SmModelSingleton to properly work with table names

I also changed the signature of MappingTableModel::addMapping for the
ease of use and added MappingTableModel::removeMapping.
MappingTableModel got 2 new convenience functions:
1. bool contains(QString) to check if an item is already present
2. QModelIndex find() to get the index of a specific value from the
model.

1 files changed, 2 insertions, 2 deletions

diff --git a/smmodelsingleton.cpp b/smmodelsingleton.cpp
index 2ee5623..7425aeb 100644
--- a/smmodelsingleton.cpp
+++ b/smmodelsingleton.cpp
@@ -51,13 +51,13 @@ QAbstractItemModel *SmModelSingleton::model(const QString &which){
 			FilesTreeModel *model = new FilesTreeModel(headers);
 			mModels.insert(which, model);
 		}
-	}else if(which == "ActorsModel"){
+	}else if(which == "actors"){
 		if(!mModels.contains(which)){
 			QStringList headers = QStringList() << tr("Actor") << tr("Id");
 			MappingTableModel *model = new MappingTableModel(headers, "actors");
 			mModels.insert(which, model);
 		}
-	}else if(which == "GenresModel"){
+	}else if(which == "genres"){
 		if(!mModels.contains(which)){
 			QStringList headers = QStringList() << tr("Genre") << tr("Id");
 			MappingTableModel *model = new MappingTableModel(headers, "genres");