[Rev 01] RFR: git-fork: add --sync option

[Erik Helin]

> Hi all,
> 
> please review this patch that adds the `--sync` option to `git-fork`. Setting
> `--sync` (either via command-line or configuration file) makes `git-fork` sync
> the fork with the upstream repository as a last step. This ensures that the
> local clone of the fork on the user's machine is fully up to date with
> upstream.
> 
> Note that I hade to shuffle some code around in `git-sync` to allow for this,
> since `git-fork` simply just calls `git-sync` to implement this feaure.
> 
> Thanks,
> Erik
> 
> - [x] Manual testing of `git-fork`

The pull request has been updated with 1 additional commit.

-------------

Added commits:
 - b4a2d986: Fix spelling

Changes:
  - all: https://git.openjdk.java.net/skara/pull/304/files
  - new: https://git.openjdk.java.net/skara/pull/304/files/e234fb97..b4a2d986

Webrevs:
 - full: https://webrevs.openjdk.java.net/skara/304/webrev.01
 - incr: https://webrevs.openjdk.java.net/skara/304/webrev.00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/skara/pull/304.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/304/head:pull/304

PR: https://git.openjdk.java.net/skara/pull/304