-Codechange: Refactor guests obtaining path exits to use an already existing function.

git-svn-id: https://freerct.googlecode.com/svn/trunk@1358 d3bf82d2-0c16-e458-5408-27be57bd1276
-Add: Initial Employee code.
-Add: Employee exit direction and movement decisions.
-Codechange: Take into account Guest specific code in Person::OnAnimate.
-Codechange: Refactor guests/staff obtaining path exits to use existing method in path.cpp.