plscheme - plscheme: Change some old lines mentioning about

Log Message:
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Change some old lines mentioning about SCM_DATACONV_FILE and fix naming of
untrusted PL shared object file.

Modified Files:
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plscheme:
README.plscheme (r1.10 -> r1.11)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plscheme/plscheme/README.plscheme.diff?r1=1.10&r2=1.11)