binary search cleanup

[Joe Neeman]

This removes our re-implementation of binary search and uses the STL
version. The main change is to remove strcmp-like comparison functions
and replace them with binary "less than" predicates.

I also include wrappers for lower_bound and upper_bound. I use these in
my working copy, but that patch isn't ready yet.

If this patch is OK, I want to do the same thing for vector_sort next.

2006-09-07  Joe Neeman  <address@hidden>

        * lily/spanner.cc (find_broken_piece): 
        * lily/spacing-spanner.cc (get_columns): 
        * lily/source-file.cc (get_line): 
        * lily/simple-spacer.cc (get_column_description): 
        * lily/keyword.cc (lookup): 
        use the new binary search.

        * flower/include/std-vector.hh: replace binary_search with
        a more STL-like version