This commit implements feature request #3. In particular, it allows the
formatter to respond to %#v and %#+v. The # flag (%#v) adds type
information to the output and the combination of the # and + flags (%#+v)
adds both type information and pointer information. This allows the
consumer a choice between displaying types, pointer information, or both.
This commit adds a new type, SpewState, which can be used to create
instances with unique configuration options. The methods of SpewState are
equivalent to the top-level functions. Full documentation and examples
are included.
Dave Collins