python - be: Convert source encoding to utf-8 for compile(src).

Log Message:
-----------
Convert source encoding to utf-8 for compile(src).

Currently, the function definition statically specifies utf-8 as the
encoding, this can be dynamically specified to the database's encoding. However,
at this time it is convenient to simply transform the encoding to utf-8 for the
sake of indent(). Once indent() and other aspects of function compilation become
more encoding independent, plpy can easily be made to compile functions without
explicit conversion.

Modified Files:
--------------
    be/src:
        pl.c (r1.20 -> r1.21)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/pl.c.diff?r1=1.20&r2=1.21)