Removed usage of bitwise assignment operators in logical operations
    
    JavaScript &= and |= are bitwise operators. They are shortened version of:
     foo = foo & bar
     foo = foo | bar
    
    In some places they were used as shortened version of logical operation and assignment.
     foo = foo && bar
    
    It lead to type conversion to Number which is wrong (0 !== false).
    
    This patch replaces such occurances with full version of logical operation and asignment.
    
    https://fedorahosted.org/freeipa/ticket/2040