glob instead of regexp

[Soh Tk-r28629]

> But your point is valid, so I suggest:
> 
> anything_without_colons -> glob pattern
> glob:foobar -> glob pattern
> re:foobar or regexp:foobar -> regexp pattern
> other:foobar -> some other matching algorithm added in the future,
>                 e.g. plain: which doesn't interpret any character
>                 in a special way.
> foobie:foobar -> hg will complain about an unknown pattern scheme
>                  "foobie".

+1 from me, except perhaps 'anything without colons' can be 'everything not begining with a flag (flag = 're:^\w+:')'.