Implementation issue #98
Add Php::class_exists implementation.
Add Php::is_a implementation.

Add is, isSubClassOf for Php::Value.
Add Php::is_a implementation.
Add Php::is_subclass_of implementation.
Fixed issue #107
Fixed Object Constructor.

The old copy constructor of Php::Object forgot the call("__construct")
Fixed a bug of HashIterator

The old implementation of HashIterator can't support `"\0"` prefix key.
I think the array and the object is different. Maybe the user didn't
want to get the private property of an object. but in an array, `"\0"`
prefix key doesn't mean private key. so we should return `"\0"` prefix
key when it is an array.
Change C99 VLA C++ dynamic array
Fix typo
Merge pull request #127 from adanlobato/master

Fix typo
Merge pull request #122 from andot/hashiter

Fixed a bug of HashIterator
Fixed a bug of HashIterator

The old implementation of HashIterator can't support `"\0"` prefix key.
I think the array and the object is different. Maybe the user didn't
want to get the private property of an object. but in an array, `"\0"`
prefix key doesn't mean private key. so we should return `"\0"` prefix
key when it is an array.
Fix typo
Merge remote-tracking branch 'upstream/master'
Fixed compatibility issue with VS2013
Merge branch 'issue#98' of https://github.com/andot/PHP-CPP into andot-issue#98
renamed fastcall.cpp to eval.cpp, and moved the Php::eval() definition to the call.h header file
minor change so that phpcpp.h does not have any changes in this project
no more exceptions for wrong eval()'ed code
Merge branch 'andot-issue#98'
Merge branch 'class_exists' of https://github.com/andot/PHP-CPP