Added i18n for buttons text.

Implemented i18n based in the ksmigrod branch without touching the
pakages and using constants for string keys.

Added serial version ids to button actions and completed some javadoc of
the constructor of WizardContainer.
Update FAQ.md

Added a little questions in the FAQ that we know are asked.https://github.com/creswick/cjwizard/blob/master/docs/FAQ.md
Merge pull request #18 from PhoneixS/i18n

Added i18n for buttons text.
Update FAQ.md
Update FAQ.md
merged FAQ
Merge branch 'PhoneixS-patch-1'