goimports -w .
Remove unneeded functions from memdb.

This commit removes some functions from memdb which only existed to satify
the btcdb.Db interface, but have since been removed from the interface.
Update TODO section of README.md.

This ability for multiple database backends has been available for a long,
long time.  Looks like this was simply not updated when the interface was
added.
convert binary Read/Write to Uint/PutUint and copy
Use NewReader instead of NewBuffer.

NewReader is slightly faster than NewBuffer, but more importantly,
ensures the data is read-only.
use strconv.FormatInt which is much faster than fmt.Sprintf
go fmt
Add errors to all interface methods.

This commit adds error returns to all of the Db interface methods except
for FetchTxByShaList and FetchUnSpentTxByShaList since they expose the
errors on each individual transaction.

It also updates all tests and code for both the leveldb and memdb drivers
for the changes.

Closes #5.

ok @drahn
Add godoc reference badge to README.md.
Use testable example and update README.md.

This commit moves the example to a test file so it integrates nicely with
Go's example tooling.

This allows the example output to be tested as a part of running the
normal Go tests to help ensure it doesn't get out of date with the code.
It is also nice to have the example in one place rather than repeating it
in doc.go and README.md.

Links and information about the example have been included in README.md in
place of the example.
Add commented imports to the example.
IMPORT PATH MODIFICATION CHANGESET
----------------------------------

Please use this changeset as the first one on top of the conformal codebase.
Note that if there are new imports, they need to be changed as part of this
changeset. In general, use "git rebase" on github.com/conformal's version
and apply this changeset first.