Log message:
-p5-Apache-Session-SharedMem -p5-Class-DBI-BaseDSN -p5-File-Binary
-p5-File-Inplace -p5-HTML-FormatText-WithLinks-AndTables
-p5-HTML-FormatText-WithLinks -p5-IPC-Cache -p5-Locale-Maketext-Gettext
-p5-Mail-DeliveryStatus-BounceParser -p5-Math-Complex
-p5-Python-Serialise-Marshal -p5-accessors-fast -p5-constant-def
Imported into HEAD.

Log message:
Import p5-constant-def-0.01 as wip/p5-constant-def.

Define compile-time constant only if it wasn't previously defined elsewhere. The
main reason is to use for debugging constants, since there is no way to change
the value, except by editing the source.