Too many open files

[David Evans]

I upped the max number of open files using ulimit from
256 to 10000 and ran my massive build again.

While the build was running I monitored the files opened
by tclsh8.5 using

sudo lsof | grep -i tcl | grep receipts | wc -l

There were 272 instances of

/opt/local/var/macports/receipts/file_map.db

open.  I think we have a file open leak.