#47 Allow entry of character ranges for easier custom passwords

[Neil Youngman]

If you want to enter a large range of characters for custom password generation, you currently have to enter them all individually. The attached patch allows you to enter ranges. Ranges are specified as square brackets containing 1 or more letter hyphen letter blocks, e.g. [f-l1-6]. Any square brackets that do not exactly match this pattern are treated as literals, not ranges. Ranges may be entered as first to last, or last to first, so [f-l] and [l-f] produce the same range.

[Neil Youngman]

Patch to PasswordGenDlg.cpp