Fix for #937
Fix for #937

As I mentioned in bolt/bolt@0640bca81d16361630ff326cadc9d47a3125b932 I encountered some errors. I figured out the url check for thumbnails is not made properly. The REQUEST_URI variable is not started with /thumbs when Bolt is running from a subdirectory. I also used timthumb.php-s check for prober url format beacuse I think we don't want malformed thumbnail url-s to redirected to timthumb.php.
hannesl/bolt,richardhinkamp/bolt,cdowdy/bolt,nikgo/bolt,CarsonF/bolt,lenvanessen/bolt,xeddmc/bolt,Intendit/bolt,rarila/bolt,rarila/bolt,rossriley/bolt,xeddmc/bolt,Raistlfiren/bolt,winiceo/bolt,pygillier/bolt,joshuan/bolt,bywatersolutions/reports-site,winiceo/bolt,GawainLynch/bolt,bywatersolutions/reports-site,kendoctor/bolt,Intendit/bolt,nikgo/bolt,marcin-piela/bolt,xeddmc/bolt,xeddmc/bolt,HonzaMikula/bolt,marcin-piela/bolt,lenvanessen/bolt,skript-cc/bolt,romulo1984/bolt,bolt/bolt,nantunes/bolt,richardhinkamp/bolt,one988/cm,rossriley/bolt,Intendit/bolt,bolt/bolt,CarsonF/bolt,Raistlfiren/bolt,Intendit/bolt,richardhinkamp/bolt,HonzaMikula/bolt,hugin2005/bolt,bolt/bolt,hannesl/bolt,hugin2005/bolt,Eiskis/bolt-base,rarila/bolt,Raistlfiren/bolt,rossriley/bolt,pygillier/bolt,hugin2005/bolt,codesman/bolt,pygillier/bolt,HonzaMikula/bolt,pygillier/bolt,nantunes/bolt,romulo1984/bolt,skript-cc/bolt,lenvanessen/bolt,Calinou/bolt,marcin-piela/bolt,CarsonF/bolt,Calinou/bolt,skript-cc/bolt,Eiskis/bolt-base,HonzaMikula/masivnipostele,HonzaMikula/bolt,HonzaMikula/masivnipostele,richardhinkamp/bolt,one988/cm,lenvanessen/bolt,bolt/bolt,one988/cm,HonzaMikula/masivnipostele,kendoctor/bolt,electrolinux/bolt,Calinou/bolt,tekjava/bolt,tekjava/bolt,winiceo/bolt,joshuan/bolt,nikgo/bolt,tekjava/bolt,one988/cm,Calinou/bolt,nikgo/bolt,marcin-piela/bolt,rossriley/bolt,cdowdy/bolt,hannesl/bolt,electrolinux/bolt,GDmac/bolt,hannesl/bolt,kendoctor/bolt,codesman/bolt,joshuan/bolt,nantunes/bolt,joshuan/bolt,GawainLynch/bolt,electrolinux/bolt,tekjava/bolt,nantunes/bolt,winiceo/bolt,rarila/bolt,GawainLynch/bolt,HonzaMikula/masivnipostele,Eiskis/bolt-base,bywatersolutions/reports-site,electrolinux/bolt,cdowdy/bolt,GDmac/bolt,GDmac/bolt,cdowdy/bolt,GawainLynch/bolt,Raistlfiren/bolt,codesman/bolt,GDmac/bolt,Eiskis/bolt-base,kendoctor/bolt,CarsonF/bolt,romulo1984/bolt,codesman/bolt,skript-cc/bolt,bywatersolutions/reports-site,romulo1984/bolt,hugin2005/bolt