Fix up the pom file for my hosting.
Fix up the pom file for my hosting.

Fix up the pom file, preparing it to be used to deploy to Maven Central.
Also fix up some whitespace issues, and lock the versions of all used plugins,
since maven couldn't apparently figure out which versions to use.

codemercenary/JMatIO,arunreddy/JMatIO,arunreddy/JMatIO,diffplug/jmatio,codemercenary/JMatIO,diffplug/jmatio