Resource names can conflict with one another.

All defines use the same underlying resource type, asterisk::dotd::file.
This has the consequence that resource names used in different defines
can conflict with one another. So an asterisk::iax { 'sam': } would
conflict with an asterisk::sip { 'sam': } even though they represent
completely different resoures.

To work around this issue, use a significative and unique prefix to
asterisk::dotd::file resources.

Signed-off-by: Gabriel Filion <gabster@lelutin.ca>