This results in significant duplicated code, but is easier to follow.
The previous code was buggy when it came to redirection handling.
Longer term tool needs to be rebuilt to use a proper Go SQL-compliant
package (yet to be written).
If e.g. rqlite is embedded in some other HTTP engine via forwarding or
something, it might not be at /; let's allow the client to talk to rqlite
in this case.
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>