basecoin-name handler example

[jbibla]

needed from @jaekwon ...

• written spec of each error type and how to use them
• should all errors be in global errors package or should each extension have their own errors?

[jaekwon]

I think the way errors are used now is good enough ATM, and we'll have to see how people deal with their error needs. I think the best thing would be to copy x/bank/errors.go, and I think anyone who wants to create their own modules will see that...

Maybe what's missing is an example module for basecoin, e.g. a handler to change the name of a user. And there, in the module dir for the basecoin-name handler, will be errors.go which includes documentation that says, this is how you do it.

[jaekwon]

Otherwise, currently the @deveop branch does use errors correctly (it's all been recently fixed). So it's good enough for making an announcement, but lets leave this open to finish the basecoin-name handler example above.