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.

Added an equivilant function to getIR() in MLSparse for columns. I thought getJC would do this but looking at the code it did something else. Therefore I added getIC (this is possibly named badly) which literally gives you the column index as an array whose i_th value is the column of the i_th entry in pr. I've also changed the pom.xml so that its version wasn't snapshot. This was so i could create the artifact and serve it off our nexus