Support React v0.3 and PHP 5.3
Use getPhpBinary() helper
Use Environment to obtain PHP binary

This improves support for HHVM by ensuring we use the HHVM binary for child processes and invoke it with the "--php" command line option.
0.3 branch should require 0.3.x React libraries (and evenement 1.x)
Merge pull request #4
Merge branch '0.3'
Revert "Support React v0.3 and PHP 5.3"

This reverts commit 28b5337939a5236e0f181eaafc2d803935b8e79f.

Conflicts:
	composer.json
	tests/AbstractProcessTest.php
Merge pull request #6 from reactphp/revert-0.3-compat

Merge 0.3 branch and revert BC commits