add Array#flatten
Merge remote-tracking branch 'origin/master' into tim/Array#flatten
implement Thread.recursion_guard (akin to MagLev and Rubinius) and use that in Array#flatten
add Array.try_convert
Attempting to implement Kernel#sleep

which appears to work, but this is my first foray into RPython goodies.
Sleeping more than once, but for a smaller net time duration

although I'd like to be able to test the zero-arg case.  Not sure how to
do that without using a Thread or similar (?)
Handling the zero-arg case for Kernel#sleep
Adding self to AUTHORS per contribution guidelines :blush:
Revisions per feedback

including less float-casting tomfoolery, asserting allowed argument
counts, and returning something closer to the real amount of time slept
per the described `Kernel#sleep` behavior.
Handling the 0..1 args case with keyword arg instead

and letting someone else raise ArgumentError.
Merge pull request #347 from pelletier/master

Alias collect to map and add some tests
A few more cleanups per feedback

including removal of the argument parsing test since it's not the
business of this test to assert such behavior and disabling the zero-arg
"big sleep" case until we have threads.
another passing spec
Correcting which error type is raised and spiffing up signature variable name.
Meant to test the unimplemented state of zero-arge case.
we pass these specs
Merge pull request #346 from modcloth/kernel-sleep

Kernel#sleep
small nits
this returns an int actually
Merge pull request #296 from topazproject/tim/Array#flatten

Missing Array#flatten