Implement Eventloop based on pecl/ev

[csaoh]

Fix #163

The tests are failing for now, but the bug (ev does not seem to work with php://temp) was reported.

[romainneutron]

This is not issue 160 but #163

[csaoh]

woops. updated !

[cboden]

This if statement should be removed. The stream handler should be removing this from the event loop, not the event loop itself. This statement currently removes the stream from the loop without notifying the listeners.

[cboden]

I installed ev through pecl install ev (version 0.2.7), ran `phpunit --filter EvLoopTest, and received the following output:

.EE.E.(libev) cannot allocate 536874976 bytes, aborting.Aborted (core dumped)

[steverhoades]

Just to document what @cboden and I have been talking about on IRC, it appears that the test is failing due to some issues with EV and how php://temp works. It appears that this was resolved for ExtEvent by the following: https://github.com/reactphp/event-loop/blob/master/tests/ExtEventLoopTest.php#L26 (see https://bugs.php.net/bug.php?id=64652).

This would also need to be added for EvLoop. @csaoh any idea what effort is left on this? I am willing to help if needed.

[romainneutron]

@steverhoades I think you should pick @csaoh 's work and continue it if you're ok with that

[clue]

This PR seems like a good starting point, thanks @csaoh!

This PR has been WIP for quite some time now and things have changed considerably since then :-)

React now consists of individual components that are maintained individually. Supporting the pecl/ev loop is now related to the react/event-loop component.

@steverhoades started porting this over to this component via reactphp/event-loop#12, so I suppose it makes sense to focus pecl/ev related efforts on this component.