Use trampoline instead of custom fiber

Merge branch 'change-billing-lock'

* change-billing-lock:
  ExpiringLock instead of require expired
  Atomic ExpiringLock

ExpiringLock instead of require expired

We *want* to try billing a little before expiry, to prevent the account lapsing.
So use an ExpiringLock to prevent double-billing races.

Atomic ExpiringLock

Merge branch 'only-bill-if-expired'

* only-bill-if-expired:
  Only bill customer if they for sure have balance and are expired
  Allow an in-transaction condition for billing
  Change multiline chain style

Merge branch 'sip-concurrency'

* sip-concurrency:
  Limit call concurrency for outbound SIP

Merge branch 'fwd-cleanup'

* fwd-cleanup:
  Try to classify URI before saving, even if timeout.zero?
  v1 is dead and everyone has been moved
  Allow finishing adming command

Only bill customer if they for sure have balance and are expired

Allow an in-transaction condition for billing

Change multiline chain style

Limit call concurrency for outbound SIP

CustomerPlan.extract

To allow building from a hash with extra keys. Makes the CustomerRepo more readable.

Postgres#query_one

Helper for queries that only return a single row.

Allow finishing admin command

Try to classify URI before saving, even if timeout.zero?

v1 is dead and everyone has been moved

Allow finishing adming command

Say what customer was affected

NoCustomer is not registered

Merge branch 'max-call-length'

* max-call-length:
  Calculate the maximum allowable call length