additional file icons needed

please provide icons for the following file extensions:

-.cxx
-.hxx
-.json

(from redmine: issue id 2198, created on 2015-04-16 by root, closed on 2015-04-17)

• Changesets:
  • Revision 2109 by Daniel van Asseldonk on 2015-04-17T12:52:43Z:

add fileicons for cxx, json and hxx. fixed #2198

• Revision 2109 by Daniel van Asseldonk on 2015-04-17T12:52:43Z:

add fileicons for cxx, json and hxx. fixed #2198