column selector / saving columns per query

[Rob Siklos]

Ok, so to recap, the issues with this patch (and my proposed solutions) are:

> 1) you don't get to save a default query unless you have a login ID

If you're logged in, default query is stored in the dbl;  otherwise, it's 
stored in a browser cookie.  Default columns are always part of the default 
query.

> 2) it only works for the "Advanced" search, and not the "Find a specific 
> bug." page

No problem - done.

> 3) make sure that we behave no worse than before if JS is not turned on

This one was a bit tricky.  Basically, it comes down to the fact that we 
need two completely separate interfaces - the one in the pictures, and 
another one that doesn't require JS.  If nobody is opposed to this type of 
double-coding, I don't mind doing it.

In the non-JS case, I wanted to just provide a link on the search page 
called "Show Display Options".  When you click on this link, it reloads the 
page with a bunch of checkboxes (like the current colchange.cgi).  However, 
without JS, I can't reload the page, since the submitting the form takes the 
user to buglist.cgi.  I can think of two solutions, none of which are very 
sexy:
a) to reload the page, submit to buglist.cgi with an extra parameter; 
buglist.cgi will notice this parameter and redirect back to query.cgi with 
the original POST params
b) when you display the display options without JS, reload the page without 
preserving the form data (annoying).

Any other comments/suggestions/ideas?

Thanks,

Rob.