multiple entity manager handling

I like your currency bundle and I want to use it in my project, but I need multiple entity manager handling. So I implemented it.
I changed the interface of the constructor of the adapter factory class.
I changed the Unit tests as well.

Here is the test result on my computer:
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PHPUnit 3.7.22 by Sebastian Bergmann.

..........

Time: 0 seconds, Memory: 8.50Mb

OK (10 tests, 69 assertions)
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I hope you like my modification and you will accept it.