Better concurrency system and memory management

Merge pull request #29 from ahfeel/feature/better-concurrency

Better concurrency system and memory management

Fix limited number of simultaneous connections to prevent timeout errors

Bugfix/connection limit (#27)

* Limited number of simultaneous connections to prevent timeout errors
* Handle device token in response class

Added setMutableContent to the payload of the notification

Added setMutableContent to the payload of the notification. (#26)

* Added setMutableContent to the right layer of the notification.

* Removed setMutableContent from Alert
Added mutable content test

Fix endless loop while executing curl

#15 Fix endless loop while executing curl (#23)

Implemented as in comment on php.net: http://php.net/manual/en/function.curl-multi-select.php#115381

Add CURL constants

0.2.5

Merge branch 'master' of github.com:edamov/pushok

Update docker image for travis

0.2.4

Update README.md

Correct loc-key & loc-args key names

Fix bug #5

Fix authenticateClient argument

Merge pull request #4 from ECOMDevelopment/bugfix/authenticateClient

Fixed authenticateClient argument