Suggestion: Improve package searches containing spaces

[Alexander Blazej <alexander.blazej@gmail.com>]

If I browse
http://www.debian.org/distrib/packages
then in either the "Search package directories" or "Search the contents
of packages" sections enter a keyword containing a space (ie "a b"), I
get a rather unfriendly and uninformative error message:

Error: keyword not valid or missing

Perhaps make spaces form a logical AND for searches, or failing that,
give an error message the reads:

Error: the keyword you entered "a b" contains space characters, which
this search feature is unable to process. 

Thanks,
~Alexander