Use only one autoloader if possible

[boekkooi]

Hi there,

So I finally had some time in my project to go on the hunt for some strange behaviour with 3.1.0RC2.
Because the project that I'm working on has a less then normal structure and behat is installed as a symlink, bin/behat managed to load 2 different and conflicting autoloaders.

Since #830 requires both autoloaders I added a simple check to see if the first/current working directory autoloader adds behat, if so when there is no need to load any extra autoloaders.

Let me know what you think.

Cheers,
Warnar

[everzet]

Thank you very much for contribution!

[boekkooi]

No problem thanks for the merge and your great work!