plscheme - plscheme: Now it's possible to have both trusted and

Log Message:
-----------
Now it's possible to have both trusted and untrusted PL/scheme in the same
database. Further modifications are listed below:

New GUC Variables
plscheme[u].module_dir and plscheme[u].cache_max_size custom GUC variables
are introduced. (With PGC_BACKEND modifier.)

plscheme-shared
Per-session shared variable plscheme-shared is re-introduced.

init.scm
A new module, init.scm is introduced. This file will get evaluted just
before every procedure execution.

Modified Files:
--------------
plscheme:
plscheme.c (r1.22 -> r1.23)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plscheme/plscheme/plscheme.c.diff?r1=1.22&r2=1.23)
README.plscheme (r1.11 -> r1.12)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plscheme/plscheme/README.plscheme.diff?r1=1.11&r2=1.12)
dataconv.scm (r1.3 -> r1.4)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plscheme/plscheme/dataconv.scm.diff?r1=1.3&r2=1.4)

Added Files:
-----------
plscheme:
init.scm (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/plscheme/plscheme/init.scm?rev=1.1&content-type=text/x-cvsweb-markup)