Update the folly/README

Summary: Now that we have an Overview.md.

Test Plan: None.
Add a LICENSE file for folly

Summary: Adds a copy of the apache license 2.0.

Test Plan: None.
Adding support for in-place use of ProducerConsumerQueue.

Summary: As it is, ProducerConsumerQueue requires that values are moved or copied on the way out of the queue. It would be nice if it was possible to get a reference to the front of the queue, use it in place, then destruct it.

Test Plan: Unit tests

FB internal diff: D484538
add a .gitignore and remove folly-config.h (generated file) from the repo
Move LICENCE and README to top level directory

Summary: For the public version of the repo.

Test Plan: N/A.
Typos.

Summary:
As pointed out by orbitcowboy at
https://github.com/facebook/folly/issues/6

Test Plan: No

Reviewers: jdelong, aalexandre

Reviewed By: jdelong

CC: folly@lists, bagashe

Differential Revision: https://phabricator.fb.com/D486754
Fix error in ProducerQueue::isEmpty

Summary:
Oops.

Also: documented the slightly confusing behavior w.r.t. 'size'.

Test Plan: Added a unit test.

Reviewers: tjackson, jdelong

Reviewed By: jdelong

CC: folly@lists, lr, bagashe

Differential Revision: https://phabricator.fb.com/D486832
Check the return value from malloc / realloc.

Summary:
https://github.com/facebook/folly/issues/7

Wrappers: checkedMalloc / checkedRealloc / checkedCalloc

Test Plan: all folly tests

FB internal diff: D486841
Add #include <new> to folly/Malloc.h.

Test Plan: folly tests

Reviewed By: philipp@fb.com, andrei.alexandrescu@fb.com

FB internal diff: D486884, D487376
Some typos corrects, and collapsed the two descriptions of Bits.h into one.

Summary: https://github.com/facebook/folly/pull/1

Test Plan: N/A.

Reviewed By: andrewjcg@fb.com

FB internal diff: D485738
Fix some memory_order parameters in AtomicHashMap

Summary: Herb Sutter noticed an error in the AHM find pseudo-code at
the C++ conference, and the error is in the real implementation too.
We should be using memory_order_acquire, because we need the load of
the key to happen before any subsequent loads of the value itself.
Our implementation is conservative for a memory_order_relaxed load
(we generate the same code as if it were memory_order_acquire---i.e. a
compiler barrier but no memory barriers), so this should not change the
generated code.  Correctness is a good idea, though (when we upgrade
to gcc 4.7's atomics it might not be as conservative).  Also, erase was
doing three loads when one is enough.  ... also fixes an exception safety
bug in insert.  (Phew.)

Test Plan: Ran the AHM unit tests, debug and opt.

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D485744
fbstring: remove reference to /home/engshare/ paths

Summary: Reported by https://github.com/facebook/folly/issues/8

Test Plan: no

Reviewed By: tudorb@fb.com

FB internal diff: D487572
EventCount: "condition variable" for lock-free algorithms

Summary:
This allows you to convert non-blocking lock-free algorithms into
blocking versions.

See
http://www.1024cores.net/home/lock-free-algorithms/eventcounts,
http://software.intel.com/en-us/forums/showthread.php?t=62364,
http://www.akkadia.org/drepper/futex.pdf

Test Plan: new test

Reviewed By: delong.j@fb.com

FB internal diff: D474570
Deuglify unaligned accesses in GroupVarint.

Test Plan: folly/test

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D488631
Add links to README.

Test Plan: No

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D489199
Add IOBufQueue::wrapBuffer, which handles buffers > 4GB.

Test Plan: test added

Reviewed By: brianp@fb.com

FB internal diff: D489158
folly::detail::futex should be inline

Summary: It breaks build.

Test Plan: will check *_try builds

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D489935
D'oh: fix size computation in ThreadLocalDetail.h

Test Plan: thread_local_test

Reviewed By: ldemailly@fb.com

FB internal diff: D490912
Typos.

Test Plan: No

Reviewed By: delong.j@fb.com

FB internal diff: D491038
Add IOBuf::takeOwnership(unique_ptr<T>&&).

Summary:
Useful for in-place serialization.  Dangerous, obviously, but anything
involving IOBuf usually is.

Test Plan: test added

Reviewed By: brianp@fb.com

FB internal diff: D491663