The metadata construct 'Key: Value' is now just a special case for
'Key:: "Value"'. Another after a :: in metadata setting is parsed as a
full value expression and typed as such. For example:
; Key:: $400 + $500
ledger -l 'tag("Key") < $1000'
Example of a tagged entry:
i 2009/11/01 12:00:00 Account Payee ; :Foo:
o 2009/11/01 13:00:00
Two spaces or a tab must separate account from payee, and payee from
note.
