Merge php:: calls into their non-php callers

[GoogleCodeExporter]

Often php:: calls have no semantic meaning. So it's probably wise to have
an option to merge these calls' time into their non-php callers.
Rationale is the following:
 1) reduce tree
 2) splitting some user function to a lot of php:: calls can divert from
semantic to technical realization that's not always good.

Example. If we have such tree:
- myFunc 10ms
  - preg_replace 10ms
  - substr 20x1ms

We could alter it to just:
- myFunc 40ms

Original issue reported on code.google.com by Alexey.K...@gmail.com on 3 Jan 2009 at 2:24