#80 Exceptions when used under heavy load with ratpacking enbabled

[Roland]

We are using pyparsing to parse form rules. This works great, but there are problems with ratpacking when the server is under load (e.g. produced with funkload), see the attached file with some tracebacks.

[Paul McGuire]

Please retest using recent pyparsing versions (2.1.7 or later). Packrat memory management has been almost completely redone, with significant performance and memory improvements.

[Paul McGuire]

Packrat cache has been completely rewritten