Fix bugs :

* QString::number use scientific format, si it's invalid for numbers > 1 000 000. We need to use v.sprintf("%d");
	* Accounts and categories where badly mapped during import
	* Fix cost not taken in account during import
	* Forbid empty account name and empty category name

src/model/import/XMLImportEngine.cpp

@@ -213,14 +213,14 @@ void XMLImportEngine::LoadOperation(const QXmlAttributes& attrs)
     op.amount = attrs.value("amount").toInt();
     op.description = attrs.value("description");
     op.category = attrs.value("category").toInt();
-    op.category = (attrs.value("fix_cost") == "1");
+    op.fix_cost = (attrs.value("fix_cost") == "1");
     op.account = attrs.value("account").toInt();
     op.checked = (attrs.value("checked") == "1");
     op.transfert = attrs.value("transfert").toInt();
     op.formula = attrs.value("formula");
     op.meta = (attrs.value("meta") == "1");
     op._virtual = (attrs.value("virtual") == "1");
-
+    
     UNESCAPE_CHARS(op.description);
 
     _operations.push_back(op);