Fix: serialization of test suits static properties
Fix: serialization of test suits static properties

When --backupStaticAttributes switch is set static properties of classes derived from PHPUnit_Framework_Test are also backed up due to wrong use of instanceof.

<string> instanceof <object>|<class>|<string> is always false. One should use is_a(<stringClassName>, <stringClassName>, true).

This bug affect all versions of PHPUnit that uses PHPUnit_Util_GlobalState class.

m157y/phpunit,stof/phpunit,tronsha/phpunit,asgrim/phpunit,simohammedhttp/phpunit,nonconforme/phpunit,HappyRay/phpunit,malkusch/phpunit,zhaoyan158567/phpunit,Firehed/phpunit,darol100/phpunit,giorgiosironi/phpunit,Shaked/phpunit,dshafik/phpunit,imshibaji/phpunit,chrisbjr/phpunit,WebSeed/phpunit,Maks3w/phpunit,kyale/phpunit,Ma27/phpunit,bradgrohs/phpunit,masarakki/phpunit,ezzatron/phpunit,sebastianbergmann/phpunit,didiwuliu/phpunit,SunDrop/phpunit,ya7lelkom/phpunit,CarsonF/phpunit,Lance0312/phpunit,lcp0578/phpunit,FireWalkerX/phpunit,eelf/phpunit,DonaldKellett/phpunit,s001dxp/phpunit,luomor/phpunit,MartinhoOmura/phpunit,9040044/phpunit,beealone/phpunit,duncan3dc/phpunit,MajorCaiger/phpunit,potherca-contrib/phpunit,OndraM/phpunit,serbanghita/phpunit,nelson6e65/phpunit,abachi/phpunit,abacaphiliac/phpunit,matheusgomes17/phpunit