XmlParser Changes

- The HashMap that the XmlParser class owns is now thread safe

- The HashMap now has generic parameters for its key and value pairs.
This removes the compiler warning as well as allowing us to only parse
the integer values once

- The XmlParser will now search for the .xml file in the project's root
directory instead of being hard coded to search inside the src folder

- I think I accidentally erased the xml file with one of my previous
commits, so this gives me the chance to re-commit it with proper input