Reduce the very large timeout value by polling the serial line.
Reduce the very large timeout value by polling the serial line.

The event reporting is improved as well, by emitting more waiting 
events.


glance-/libdivecomputer,glance-/libdivecomputer,josh-wambua/libdivecomputer,Poltsi/libdivecomputer-vms,henrik242/libdivecomputer,venkateshshukla/libdivecomputer,josh-wambua/libdivecomputer,henrik242/libdivecomputer,andysan/libdivecomputer,andysan/libdivecomputer,venkateshshukla/libdivecomputer