Delay first sync after sync client starts for n seconds

### Feature request: Delay first sync after sync client starts for n seconds
It would be super nice to have the possibility to make the sync client wait a few seconds after it has been started to do it's first sync. This would be useful to prevent heavy disk usage when the user most likely needs it.

#### Example:
When I boot up my computer, the sync client starts automatically. This is fine and as I want it. But it also automatically starts scanning every directory for changes immediately which slows down my disk quite heavily and therefore increases the time needed for other programs to start. When I log in to my computer, I usually want do do things asap. Eg. Browsing web or checking e-mail. The sync client effectively slows down the start of other programs (which I start manually). Especially the browser.

If there would be a way to tell the sync client "please wait for two minutes before you do anything", I could start up everything fast and when everything is loaded, the sync client could start syncing happily. As for me it is unlikely that anything has changed on the server and I need the sync asap.

Two minutes is just an example which would work for me. I'd love to see this implemented as an opt-in feature. Eg. the default delay is 0 seconds. (current behavior)