Java API changes

[tkutz]

With the v4 release we have the opportunity to change the APIs to improve the naming.

State names:

• Enumerator names should be upper case (see also #1000)
• No need to prefix the names with the statechart, as the state enum is inner class of statechart class

Statechart Interface Access:

• Default/unnamed interface should be named Interface, instead of SCInterface
• Named interface should be named Interface[name], instead of SCI[name]
• Change getter names accordingly: getInterface(), getInterface[name]