Fix ChromePhp logger interface and debug level

[xoob]

The ChromePhp log writer logs debug messages as error messages. It looks like the interface was copied from FirePhp and not updated.

This pull request changes the ChromePhpInterface to match the actual class and fixes the log level used for debug messages.

[prolic]

We can only change that interface for ZF3. Can you find another solution?

[weierophinney]

@prolic Actually, it appears that this is a matter of just moving things around; we already have a log method in the interface, and @xoob appears to have swapped the log and error method placements in the interface.

[weierophinney]

That said... @xoob -- additions to an interface are not backwards compatible, nor is removing a method (I see you've removed trace and added group). Which is problematic, as I'm not sure how we can expose these features otherwise.

My guess is nobody else will implement the interface; they'll likely only ever use the writer we provide. Let me bring this to the community review team to discuss.

[xoob]

@weierophinney Understood, makes perfect sense. I'm not sure why the interface defines a trace() method though, but I suspect it is by mistake.

The actual ChromePhp class that is called defines this:

public static function getInstance()
public static function log()
public static function warn()
public static function error()
public static function group()
public static function info()
public static function groupCollapsed()
public static function groupEnd()
public function addSetting($key, $value)
public function addSettings(array $settings)
public function getSetting($key)

[xoob]

Reverted the original fix and made another one that just changes the error() call to log(). Long-term I think it's still a good idea to update the ChromePhpInterface to match the actual ChromePhp class though.