Generalizes the telecommunication reception check.

Also happens to fix a bug where a Detomax could blow up PDAs without reception.
Changes a couple of type checks to access checks.
PDA newscaster

One can one access and view newsfeeds from the comfort of one's PDA.
Possible to change and disable the newsmessage beep.

Known issues:
Unlike browse() NanoUI does not appear to wait for browse_rsc(), the method which to transfers image to the client's cache, to finish.
This often results in newsfeeds not always displaying their images the first time they are viewed.
Merge pull request #6865 from PsiOmegaDelta/PDA

PDA newscast reception