Fix an exception when saving settings while having the Port field left empty
Rename the 'Clear' button to 'Default' because that's how it actually functions. Crosses one item from the TODO.
When using the Default button in the Settings form we now set the 'Hide password' checkbox to checked if the user is watching the connection tab rather than the 'Other' tab. Also fixed minor typo in previous commits
If the port settings were set to 0, we set the Port field to empty instead of 0 when loading them into the loginform textbox holding its data