[f0f876c141] Improve consistency in error messages.
# Enter commit message for this check-in. Lines beginning with # are ignored.
#
# user: dkf
# tags: trunk
#
# EDITED     generic/tclClock.c
# EDITED     generic/tclCmdMZ.c
# EDITED     generic/tclFCmd.c
# EDITED     generic/tclIOCmd.c
# EDITED     library/clock.tcl
# EDITED     tests/clock.test
# EDITED     tests/exec.test
# EDITED     tests/fCmd.test
# EDITED     tests/ioCmd.test
# EDITED     tests/regexp.test
# EDITED     tests/regexpComp.test
# EDITED     tests/string.test
# EDITED     tests/subst.test
# EDITED     tests/switch.test