Component based logging

[d1vanov]

Current libquentier's logging system has no concept of components. Components could represent context for different logs, like logs of local storage, logs of synchronization, logs of UI models, logs of UI views etc. Filtering logs based on components can produce logs which are much easier to deal with because they contain only the info one is interested in but no useless distracting entries one has to skip over to get to the needed info.

The suggestion is to add the ability to specify components in libquentier's logs. Need to think whether it can realistically be done in one go or a gradual migration from old componentless logs format would be required.