Fix typos in some error messages thrown by extension scripts when fed to psql.
Some of the many error messages introduced in
458857cc missed 'FROM
unpackaged'. Also
e016b724 and
45ffeb7e forgot to quote extension
version numbers.
Backpatch to 9.1, just like
458857cc which introduced the messages. Do
so because the error messages thrown when the wrong command is copy &
pasted aren't easy to understand.