Fixed race conditions in Child and Pool classes

Kudos to @damoclark 🍺

Best use of exceptions

• Base exception marker interface for the library
• Custom exception classes based on the native PHP ones
• Update Process interface: methods kill(), terminate() and wait() should not throws exception anymore but return its success or failure
• Update Child class according to the new interface
• Update Pool class according to the new interface

Use PHPFluent\Callback to run callbacks

1.8.0

Use PHPFluent\Callback to run callbacks

Improve PHP unit tests

• Add "composer.lock" file to the repository
• Add autoload-dev directive to "composer.json" file
• Add instalation of "uopz" PECL extension in Scrutinizer settings
• Add instalation of "uopz" PECL extension in Travis settings
• Convert Exceptions to array on Context::toArray()
• Create methods overwrite() and restor() on Arara\Test\TestCase class to help overwriting and restoring PHP functions
• Move TestCase class to Arara\Test namespace
• Move PHPUnit unit tests to "tests/unit"
• Remove "bootstrap.php" file used as boottrap in PHPUnit test suite
• Remove "event" property from Context object
• Remove pcntl_* and posix_* overwritten functions
• Remove checking of JSON_PRETTY_PRINT constant from code examples
• Remove PHP 5.3 version from Travis settings file
• Remove support for version 5.3 of PHP
• Update "composer.json" file with the minimum supported PHP version
• Update "README.md" icons (Travis, Scrutinizer, Packagist, Bitdeli)
• Update "README.md" with the minimum supported PHP version
• Use "uopz" PECL extension to overwrite functions

Create Command action

1.6.0

Create Command action

Create Daemon action class

• Create Daemon action class
• Create method on Control class to flush memory and sleep
• Improve Callback action class
• Improve Child and Action events
• Improve Pidfile class

Allow more than one handler for the same signal

1.4.0

Allow more than one handler for the same signal

Use an object as context instead of an array

1.3.0

Use an object as context instead of an array

Centralize handlers for signals and PHP errors

• Move signal handlers to Arara\Process\Handler namespace
• Create SIGALRM handler class
• Create PHP error handler class

Create method `getPid()` on Pidfile class

1.1.2

Create method `getPid()` on Pidfile class