removed ata ( ) in lsqadj.{c,h}
renamed ata_v2 into ata
added explanation and the test to check_lsqadj.c
removed atl ( ) renamed atl_v2 into atl ( )
added test_atl () to check_lsqadj.c
removed matinv (), renamed matinv_v2 into matinv () and added test_matinv ()