Output booleans as 1/0 in XML

bool false was outputted as an empty string in XML while true was outputted as int 1. Now false is outputted as int 0 for consistency
Added unit tests for boolean representation in json/xml output
fixed error in unittest
Merge pull request #12 from chrisramakers/master

XML output for false changed from empty string to int 0
Merge branch 'master' of github.com:blongden/hal into feature/decode

Conflicts:
	tests/Hal/HalTest.php