[regress/sftp-glob.sh regress/test-exec.sh] remove "echo -E" crap that I added in last commit and use printf(1) for cases where we strictly require echo not to reprocess escape characters.
[regress/sftp-cmds.sh regress/sftp-glob.sh regress/test-exec.sh] comprehensive tests for sftp escaping its interaction with globbing; ok dtucker@
[Makefile sftp-glob.sh] some globbing regress; prompted and ok djm@