Implementation of most Jdbc4 methods

Implementations for Jdbc 4 and 4.1 methods that were left unimplemented, with the exception of methods concerning data types (lobs, rowid, Ntypes, ...).
* Connection.abort
* ~~Connection.setNetworkTimeout / Connection.getNetworkTimeout~~
* Connection.setSchema / Connection.getSchema
* Statement.closeOnCompletion / Statement.isCloseOnCompletion
* Array.free

And some specification fixes