Permit replacement of pin_factory without closing old factory. However,
continue closing devices associated with extant pin factory at script
termination.
The real pin tests were broken by the new factory stuff. This commit
fixes them up, and fixes up a few other bits besides (like why the
pigpio PWM tests were failing, why RPi.GPIO sometimes segfaulted on PWM
tests, etc.)
It also causes the real pin tests to run against MockPin (thanks to
@lurch for the suggestion!). This required some tweaks to MockPin to
make it emulate physically pulled up pins itself (which in turn
necessitated changing quite a few pin numbers in the main test suite
because we were using 2 and 3 everywhere), and to allow one MockPin to
drive another. Anyway, everything's working now including all the tests
on a Pi (haven't tried RPIO yet, but only because I'm on a Pi3 -
everything else works with overall coverage of 88% :).
Sorry! Dave's messing around with the pin implementations again.
Hopefully the last time. The pin_factory is now really a factory object
which can be asked to produce individual pins or pin-based interfaces
like SPI (which can be supported properly via pigpio).
Change MockPin (and MockPWMPin) to make them behave more like 'real' pins - fixes#206
Add new MockPin tests, and rework some of the existing ones
Incorporate #216
