hgk: simplify tags parser As when hg tags is being called without -v option, it returns lines with two elements in each, we can just interate them as if it were a usual Tcl list using foreach and two variables. Line endings and whitespace don't matter when doing so, so we may keep them as is. When we're processing the lines, tag variable is assigned a tag name, and rev is a string in form of revision:hash which we can split on colon. As Tcl8.4 lacks lassign command, and using lindex makes code a bit less readable, we use foreach to iterate over two-element list.

hgk: add support for phases Add support for phases. Update tests.

hgk: in popups, replace labels with window titles Replace labels with window titles. That also requires to change grid placement manager settings to compensate padding which used to be applied to now non-existent labels.

hgk: update backgroud colour when Ttk is available Ttk doesn't automatically set up Tk colour palette. Because of that, Ttk controls look differently when used together with old Tk controls. When we use Ttk controls, we first query if we have any setting for the client background, and if we do, we update Tk palette as well.