Engine.java mods for 1.8-dev

[Mark Washeim <es...@canuck.com>]

I'm forwarding some mods that we've made to the Engine to better handle 
multiple requests under duress.

In brief, we've added an inner class (block) which functions to put a block
on threads requesting the page instance in question until the first request
for said page is in cache. The net effect is to ensure that xsp or other
page types are only processed by the first request and ALWAYS consequently
retrieved by further requests, from cache.

We're running these changes in production and they seem stable. Any
questions or thoughts, please direct to me personally as well as to the
list. We'd be happy to improve the method whereby the effect is arrived at.
The inner class is probably not the best solution . . .

Regards,
Mark Washeim
Large Medium, AB