Fixing code generation for invalid templates.
Merge branch 'fix-invalid-templates' of git://github.com/elasticsales/pybars into elasticsales-fix-invalid-templates

Conflicts:
	pybars/_compiler.py
	pybars/tests/test_acceptance.py
Tweaking backslash behavior
Backslashes should only escape quotes in string literals. In all other cases, backslashes should be interpreted literally