TIDOC-1081 Add new platforms and remove duplicated code.

- Centralize list of platforms, platform names.
- Added tizen and blackberry platforms.
- Add "is_pseudotype" field to annotated objects to remove duplicated code in various generators.
- Make docgen fail fast if a generator script has a syntax error (i.e., exit before parsing YAML).

Note that the new platforms will break JSDuck unless this is tested with the corresponding pulls for JSDuck and doctools. (PR links to follow)