. make common.o link with the tests instead of being
#included as common.c
. fix warnings about missing prototypes by declaring functions
static
. reduces some duplicated code
Change-Id: Ic2a765d7f5886add5863190efec3fdd2d2ea2137
Make test40 behave better. It should create its own subdirectory to
conduct its tests and should not write to /tmp. Also, the master-slave
terminal pair it tries to open might be in use; it should try to obtain
another pair. These changes allow the test to be run multiple times
simultaneously from different paths (to test select() more intensively).