CYB-148, new pages for maintenance, 404 and 500 errors
CYB-148 - updated pull request, removing the 500 error and moving the 404 to the Angular 404 file
Merge branch 'CYB-148' of https://github.com/elicochran/datacultures into CYB-148
CYB-148 - Made error messages a bit friendlier