#9 Upgrade to Java SE 7

[Alcibiade]

If we decide to drop support for Java SE 6 and move to SE 7, we should provide some added value:

• Upgrade exception handling in various connectors to use resources
• Declare connectors as closable resources
• Upgrade file access, mainly in the local FS connector, to use NIO

The latest is mandatory for consistent symbolic links management in UNIX FS synchronization.