Parse a full set of UI Options &idspec=...,..

Underlying handlers should call this to get their session object.

Should be a simple list, really.

icaoid=A12345 - lookup recent flights on that airframe.

If no times specified, defaults to day before yesterday.

RGrDeleteHandler - (key,index).

RGrEditHandler - (key,index [,form]) if form, edit&save, chain to ./grs/edit; else render [gr-edit].

RGrsDeleteHandler - (key) delete it, chain to ./list.

RGrsEditHandler - (key [,form]) load it; if form, edit&save, chain to ./list; else render [grs-edit].

RGrsnewHandler - () conjure empty grs, render [grs-edit].

RGrsViewHandler- (key [,idspec]) load it, go to [grs-mapview].

This is a kind of abuse of ColoringStrategy from colorscheme.go.

WithFdb does a few things: creates a context, requires user to be logged in (redirecting if they're not), looks for report options and injects them into context if found, and then finally calls the FdbHandler.

WithFdbAdmin either requires an admin user, or that the request comes from within appengine.

WithoutFdb allows a regular contexthandler to be embedded into an FDB handlerware chain.

Old ones, for trackpoints.

No '#' on this one.

Wrap up in a datastore-friendly struct.

MapShapes is a single thing that contains all the things we want to render on a map.

Common parameters for UI rendering, as parsed from CGI params.

Rather than stash/retrieve an FDB object from the context, we'll just pass it directly to a new handler type, that we'll use throughout ui/.