Add support for underscores in names

[vrecan]

We have fields that start with underscore that get mangled during code generation.

[drslump]

The behaviour of the camelize function is to provide accessor methods which feel more natural to common PHP code conventions.

It will provide the following transformations:

• user_name -> hasUserName, getUserName, setUserName
• _private_field -> hasPrivateField, getPrivateField, setPrivateField

I don't see how this solves the problem for fields starting with an underscore. Perhaps it would be better to change the camelize function to the following:

if ($name[0] === '_') return $name;
return preg_replace_callback(
                '/_([a-z0-9])/i',
                function($m){ return strtoupper($m[1]); },
                $name
             );

Which will leave unmangled any field starting with an underscore, providing the following transformations:

• user_name -> hasUserName, getUserName, setUserName
• _private_field -> has_private_field, get_private_field, set_private_field