[RFA] convert blocks to dictionaries, phase 1, main part

[Andrew Cagney]

David,

Some brief stylistic notes (ref 
http://sources.redhat.com/gdb/current/onlinedocs/gdbint_13.html#SEC113)

- create a header ``dictionary.h'' / ``nametab.h'' / ... that defines 
the interfaces for this new object.

- macro's are bad m'kay :-)

- the function names should be lower case

- just implement interfaces sufficient for the immediate needs.  For 
instance, instead of providing ``enum dict_type'', just describe the 
idea.  Since we can compile with -Werror, changing internal interface, 
when there is evidence that it is actually needed, has become relativly 
easy.

- keep gdbint.texinfo in mind

- you'll want to start compiling all targets

enjoy,
Andrew