Maven support for HunspellJNA

Flemming,

these are the changes that add Maven support for HunspellJNA.
I took the [pom.xml by Thomas Joiner](https://gist.github.com/thomas-joiner/3295061) as a starting point and made customizations to it so that Maven would obey to your project layout.

Once you integrate the changes, it would be possible to apply for Maven Central inclusion,
thus fixing issue #2.