Small code fix

[Ruddles]

Have a small fix to stop people opening up 2 instances of the updater up at the same time, thus stopping people (in theory) getting the "access is denied" error because the file is already locked:

In Public Sub New() under the comment "'Add any initialization after the InitializeComponent() call":

Dim gotit As Boolean
Dim mut As New Mutex(True, "EQ2UpdateMut", gotit)

This creates a Mutex that is locked til the program ends. If you start another instance of it up then it tried to get access to this mutex, can't, and exits nicely with "1 instance" error message.