Updates to pom in attempt to streamline release process
Add PSTFile.close()

Since PSTFile's constructor opens a RandomAccessFile it stands to
reason that a user of this class will want to explicitly control when
this file is closed.

This patch adds the close() method to PSTFile in order to allow
this capability.
fixes #23
fixes #22
Merge branch 'develop' into feature/2013-ost-support