Add passwords with user-specified special characters #585

[leoncho]

This adds the feature requested in #585.

This adds support for generation of passwords with inclusion of user-specified special characters. The user can be used to specify the set of allowable special characters (eg. !,@,$,%,^) that will be randomly included in generated passwords. This feature can also be used for internationalization to support international characters sets in ASCII and UTF-8.

JUnit tests are included for both general and international character sets.