Progress!

Masked error caused by saving dbc while editor is open that causes
msg IDs to go crazy by making editor modal, but that affects all
other windows, so might be a better fix.

Added new value type of VALUE_STRING, probably better named
ENUMERATED_STRING, and it uses the table in the editor to define
the enum.

Fixed a bug in the signal viewer load when a signal is not matched
(I found it by renaming a signal and then loading)

dbc/dbcsignaleditor.cpp

@@ -34,6 +34,7 @@ DBCSignalEditor::DBCSignalEditor(QWidget *parent) :
     ui->comboType->addItem("SINGLE PRECISION");
     ui->comboType->addItem("DOUBLE PRECISION");
     ui->comboType->addItem("STRING");
+    ui->comboType->addItem("ENUMERATED STRING");
 
     ui->bitfield->setMode(GridMode::SIGNAL_VIEW);
 
@@ -84,7 +85,10 @@ DBCSignalEditor::DBCSignalEditor(QWidget *parent) :
                     break;
                 case 4:
                     currentSignal->valType = STRING;
-                    break;                    
+                    break;
+                case 5:
+                    currentSignal->valType = VALUE_STRING;
+                    break;
                 }
                 dbcFile->setDirtyFlag();
                 fillSignalForm(currentSignal);
@@ -577,6 +581,9 @@ void DBCSignalEditor::fillSignalForm(DBC_SIGNAL *sig)
     case STRING:
         ui->comboType->setCurrentIndex(4);
         break;
+    case VALUE_STRING:
+        ui->comboType->setCurrentIndex(5);
+        break;
     }
 
     for (int i = 0; i < ui->comboReceiver->count(); i++)