Would it be possible to factor out this pagespec 
code so that other plugins can use it without enabling attachments?
I am interested for [[todo/mbox]] --[[DavidBremner]]

> I can split out all of them except for `ip()` and `user()` easily. I
> have just changed the code so the rest will test the existing source file
> is no other filename is specified. Do you have any reason to want to
> check ip addresses and user names? Not sure what to call the plugin, but
> breaking it out is easy enough. --[[Joey]]

>> I don't think `ip()` and `user()` necessarily make sense for a mail box 
>> that is already on the disk, so no, I don't think I'll miss
>> them. --[[DavidBremner]] 

>>> Done, [[plugins/filecheck]] --[[Joey]]
