rename old 'check' target to 'sparse'
rename old 'check' target to 'sparse'

ifduyue/libusual,ifduyue/libusual,markokr/libusual,rabbitt/libusual,mgjv/libusual,ifduyue/libusual,markokr/libusual,markokr/libusual,mgjv/libusual,rabbitt/libusual,rabbitt/libusual,rabbitt/libusual,markokr/libusual,mgjv/libusual,ifduyue/libusual,mgjv/libusual