Move all tests from test/{od,sha1sum,shred,stty} to tests/misc/.

Move all tests from test/{od,sha1sum,shred,stty} to tests/misc/.

Reflect these renamings:
od/od-N             misc/od-N
od/x8               misc/od-x8
sha1sum/basic-1     misc/sha1sum
sha1sum/sample-vec  misc/sha1sum-vec
shred/exact         misc/shred-exact
shred/remove        misc/shred-remove
stty/basic-1        misc/stty
stty/invalid        misc/stty-invalid
stty/row-col-1      misc/stty-row-col

* tests/misc/Makefile.am (TESTS): Add the new files.
* tests/Makefile.am (SUBDIRS): Remove the dir names.
* tests/od, tests/sha1sum, tests/shred, tests/stty: Remove the directories.
* configure.ac (AC_CONFIG_FILES): Remove the corresponding Makefile names.