Import primers dialog errors

I. The "Import Primers" dialog is not modal.
1. Open the Primer Library.
2. Click "Import primer(s)".
Expected: the dialog is modal.
Actual: It is shown in the Windows taskbar as a separate window.

II. The "Remove" button is disabled.
3. Add human_T1.fa.
4. Click the added item.
Expected: the "Remove" button is enabled.
Actual: the "Remove" button is disabled.

III. The OK button is enabled.
5. Choose "Shared database" in the combobox.
Expected: the "OK" button is disabled because the list is empty.
Actual: the "OK" button is enabled.
Note: When you open the dialog the OK button is enabled but the list is empty.

IV. The OK button is disabled.
6. Choose "Local file(s)" in the combobox.
Expected: the "OK" button is enabled because the list is not empty.
Actual: the "OK" button is disabled.