ChildTicketTreeMacro fixes and enhancement

[Omi Afgani]

Hi all,

I've had to make some trivial fixes to this macro to get it working on Trac 1.6. I've also added a progress bar feature that works in ticket fields without an explicit ticket id. See: https://trac-hacks.org/ticket/14397

As mentioned in the ticket, given that there doesn't seem to have been much activity on this plugin in several years, I'd be happy to take on a maintainer role on this macro to get the changes committed to SVN.

Thanks.

[Omi Afgani]

Hello admins,

Given that there hasn't been a response from the maintainer for this hack, may I please have write access to the repository to commit the fixes?

Thanks.