also make search do something usefull when easybuild-easyconfigs are not installed

Search will now look in the cwd by default if it can not find an easyconfigs installation.
 * `search <string>` will recursively look into the current directory and subdirectories
 * `-r <path>` will keep working as it does 
 * `-r ` will exit with the message that it cannot locate easyconfigs