python - be: Add IsArray macro.

Log Message:
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Add IsArray macro. (Doesn't check if it's a "real" array)

Modified Files:
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be/include/pypg:
type.h (r1.6 -> r1.7)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/type.h.diff?r1=1.6&r2=1.7)