Updated htmlunit jar files
Changed generated class comment
Changed version in make file to 2.13
Converted HtmlUnit by running make.cmd
Ran the generator
Removed old generated files
Added new generated files to solution
Removed old unused partial classes
Obsoleted and redirected deprecated properties from htmlunit
Manually fixed minor issues in generated files
Updated nuspec
Merge pull request #4 from timorzadir/dev-2.13

Merged @timorzadir's HtmlUnit 2.13 upgrade into master.