Adjust min/max warnings for single parameter with Zend

Summary: Zend is a bit inconsistent with handling invalid parameters passed to min()/max():
```
min(1) - null + warning
min([]) - false + warning
min(new stdclass) - null + warning
```
This change retains original behavior. Makes 4 bad zend tests happy.
Closes https://github.com/facebook/hhvm/pull/3954

Reviewed By: @paulbiss

Differential Revision: D1610552

Signature: t1:1610552:1414623579:6a54b1389f5b9cd96c05c607b96a51ad40e138fd

Pulled By: @ptarjan
HackStrictOption s/ERROR/ON/

Summary: This catches me every time. The ini values are off, warn, and on but the code doesn't match those. These aren't always errors too, they are sometimes just migrations to make the language better at runtime.

Reviewed By: @paulbiss

Differential Revision: D1646037

Signature: t1:1646037:1414598255:38b81a7ff150f575a7cda6aaf8a97a3b90f62693