Add ST_GraphAnalysis

This is a really huge PR. Next time, I'll break it into smaller chunks.

Some things to note:

1. Remove `ST_ClosenessCentrality`. This has been replaced by `ST_GraphAnalysis` which is faster anyway.
2. Add [`GraphCreator`s](https://github.com/agouge/gdms-topology/tree/GH/src/main/java/org/gdms/gdmstopology/graphcreator) (and remove `GraphLoaderUtilities`). This simplifies loading a graph from a `DataSource`.
3. Add [function parsers](https://github.com/agouge/gdms-topology/tree/GH/src/main/java/org/gdms/gdmstopology/parse) which simplify multiple function signatures for SQL functions.
4. Add [AbstractExecutorFunctionHelper](https://github.com/agouge/gdms-topology/blob/GH/src/main/java/org/gdms/gdmstopology/centrality/AbstractExecutorFunctionHelper.java). This helps automate a lot of  the tasks that are common to the implementations of SQL executor functions.
4. Add `ST_GraphAnalysis`. For now, we compute betweenness and closeness. Since the progress monitor is not currently working in OrbisGIS, I made my own progress monitor which prints output to the console.
5. Change the bundle category to "Network Analysis". This should facilitate locating the plugin within the plugin manager.

This version of GDMS-Topology uses [GraphHopper-SNA](https://github.com/agouge/graphhopper-sna) which currently uses [GraphHopper](https://github.com/graphhopper/graphhopper).