Workaround for autoloading when using php namespace.

Workaround for autoloading when using php namespace.

This is a Workaround for PHP bug <https://bugs.php.net/bug.php?id=49143> (5.3.2. is broken, it's fixed in 5.3.6):

Strip leading backslashes from class names. When namespaces are used, leading backslashes are used to indicate
the top-level namespace, e.g. \foo\Bar. When used like this in the code, the leading backslash isn't passed to
the auto-loader ($className would be 'foo\Bar'). However, if a class is accessed using a string instead of a
class literal (e.g. $class = '\foo\Bar'; new $class()), then some versions of PHP do not strip the leading
backlash in this case, causing autoloading to fail.

amended: as per Jeroen's suggestion, used // for comments and ltrim instead of preg_replace.

Change-Id: I71e0429ed1da5c83262dbf6f989c782385af9bcb