#140 tlp_get reports immediately TRDP_TIMEOUT_ERR for a subscription with TRDP_TIMER_FOREVER

[Joachim Lillich]

Steps to reproduce:

1. Create a subscription with tlp_subscribe(timeout = TRDP_TIMER_FOREVER )
2. Call tlp_get() and observe a return value of TRDP_TIMEOUT_ERR.

When a subscription is done and the timeout is set to infinity, newPD->timeToGo is set to zero.
When tlp_get checks the timeout, it compares pElement->timeToGo with the current time. Since timeToGo is zero, the current time is greater than timeToGo and the timeout error is signaled.

[Bernd Löhr]

TRDP_TIMER_FOREVER was not accessible for user, needs to be defined in trdp_types.h