Centralize code for resource limit setting

Imported From: http://groups.google.com/group/in-portal-dev/browse_thread/thread/e7605f8943ab94fc#

Right now following code is copy-pasted in multiple places in In-Portal:

set_time_limit(0);
ini_set('memory_limit', -1);

I propose, that we can move it into a new function and use it instead in
all places. Here are the benefits:

   - it's auto-completed, so less chances to make typo error in setting name
   - we can add parameters to it allowing setting custom memory & time
   limits
   - we can easily track all code, that uses it to determine code, which
   heavily uses system resources

Task:

Ready for testing.

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Best Regards,

http://www.in-portal.com
http://www.alex-time.com