[SYNC] Synchronize with core. New meaning for -api option:

- Synchronize with core
- old -api option becomes -fullscan like in core
- there are three options now for retrieving redirect pages:
  - xml from xml dump
  - fullscan scans all pages (via api if available)
  - moves scans all moved pages
  if none of these options are given,
  it retrieves redirects from special page
- mark -api option as deprecated
- remove old deprecated -number option and it's deprecated warning
  (This warning has been implemented 18 months ago which should
  be enough
- doc changed

Change-Id: I51de44d0f25bf5a1881613f5ba9badb7c4dbb9aa
Merge "[SYNC] Synchronize with core. New meaning for -api option:"