Thanks to jmp-fwdcalls' 677c376, we can finally add outgoing call
support to jmp-register. This is done by creating SIP accounts for
users automatically at signup time, and then providing them with the
requisite details to make outgoing calls using the generated account.
Note that no new Catapult application is required - the existing
application used by sgx-catapult (and jmp-fwdcalls) is sufficient to
handle outgoing calls (plus incoming) due to jmp-fwdcalls' 677c376.
Aside from register4, which creates the SIP accounts, no changes to
any of the register* pages were needed, since the signup flow remains
the same. Users can now use the Catapult SIP account for receiving
calls if they like, but that is handled the same way as any other SIP
account, so no changes to register5 or register6 were required.
The text has been updated in a variety of places to indicate that
bi-directional calling is now supported.
This change also makes somewhat-related copy edits to bump up the
number of allowed voice minutes for upgraded accounts from 60 minutes
to 120 minutes per month. This makes sense since we now support calls
in both directions (not just incoming).