Icons for OC

- new icons for opencaching
  - see all icons here: https://dl.dropbox.com/u/49879320/cgeoattributes/iconlist1res.html
  - see original icons here: https://dl.dropbox.com/u/49879320/cgeoattributes/ocicons.html
- changed some old icons because of copyright
- english strings for opencaching attributes
- german strings for opencaching attributes
- new script to show (missing) strings for attributes
- new script to edit svg files from thenounproject.com
- new script to generate enums
- description how to make icons (readme.txt)
- ocicons.html: list of all OC icons