Enable warnings on specs
lazily load the number of cores + test coverage

Since this was happening when the class was loaded, it was impossible to
test.  Also, problems during this load can bring down an app during
startup, which is not desired.
env var can avoid blowing up

This maintains the default behavior, but allows one to avoid it, e.g. in
a development environment where it doesn't really matter.
Merge pull request #410 from davetron5000/dont-die-querying-cores-during-a-require

Dont die querying cores during a require
treat TerminationRequest as SystemEvent

TerminationRequest < SystemEvent, so the 'instance_of?' is a mistake.
Use Windows NUMBER_OF_PROCESSORS for Cygwin
Merge pull request #413 from douglaswth/use_windows_number_of_processors_for_cygwin

Use Windows NUMBER_OF_PROCESSORS for Cygwin
Merge pull request #412 from chronomantic/avoid_raise_wtf

treat TerminationRequest as SystemEvent
More detailed error message on unexpected message type

This error throws from time to time in our specs. We suspect it's a race condition, but it'd be nice to have some more detail in the message when it fires.
Merge pull request #414 from bluepojo/patch-1

More detailed error message on unexpected message type
2.1.0 -> 2.1.1 on Travis
give better rspec messages by using default stubs
rework core detecting + refactor tests

  * avoid setting @cores if it's going to be returned anyway

  * handle exception when NUMBER_OF_PROCESSORS is empty string

  * handle *BSD group along with Dragonfly BSD

  * use IO.read + exception handling instead of File.exist?

  * group tests by os type

  * support using NUMBER_OF_PROCESSORS to override detection on EVERY os

  * test showing error (stderr)

  * use sysctl '-n' parameter to make things more robust

  * remove CELLULOID_IGNORE_CORE_COUNTING_ERRORS and error handling
Merge pull request #415 from chronomantic/rework_core_detecting

Rework core detecting
CPU counting fixups
Add PoolManager#size= to allow for on-the-fly adjustment of pool sizes
Terminate detached workers
map the futures, not the actors themselves
Merge pull request #417 from cheald/pool_shutdown_fix

Map the futures during Pool#__shutdown__, not the actors themselves
Merge pull request #416 from cheald/adjustable_size_pools

Add PoolManager#size= to allow for on-the-fly adjustment of pool sizes