Martin Atkins 6052cb9938 zclsyntax: parse expressions in newline-ignoring mode
This applies both two the whole of bare expressions and to any nested
expressions within parentheses. The latter means that an attribute value
can span over multiple lines if it's wrapped in parens:

    foo = (
        1 + 2 + 3 + 4 + 5
    )
2017-06-02 07:26:45 -07:00
..
2017-05-13 17:44:11 -07:00
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