Updated settings for UNItopia (64 bit).
Implement __FUNCTION__ predefine. (#811)
Only define __PCRE__ when PCREs are actually available (now that we removed the builtin package).
When compiling test for PCRE put -lpcre into $LIBS.
(Some linkers need the libraries given after the program that needs them.)
Fixed information about memory being freed.

Unused memory in allocated mappings is not freed after the function
execution ended, but during data-cleanup or garbage collection. This
can take quite some time. Fixed this information and explained about
the data cleanup in the remarks.