If the replication fails using the current config, we retry
immediately using another config, without waiting anything at
all.
Only when we have unsuccessfully tried with all servers, will
we wait a while before starting again.
0 cannot be used to indicate failure as 0 will be the waiting
period if we switch to an alternative server.
Also fix some minor issues; failure to initialize all members
and inverted success-check.
Separating the reading of the config from the process of
applying it allows us to use configs around and later apply
them (e.g. when we decide its time to switch master server).
At save time, assert that the configuration as dispersed around
blr and as stored in the config object are identical.
Later its the state from the config object that will be saved.
Alternative masters can now be specified like
CHANGE MASTER TO ...
CHANGE MASTER ":2" TO ...
CHANGE MASTER ":3" TO ...
Now only the data is stored, but it is neither used nor
saved.
