Sql-sync fails on when remote is OS X/BSD in some cases

[jbrauer]

Not sure how I only found this now but in running sql-sync this line https://github.com/drush-ops/drush/blob/master/commands/sql/sync.sql.inc#L344 has the following command:

stat --format="%Y"

This isn't supported on OS X 1.5.8 or 1.9 that I tested on. It produces this error...
$ stat --format
stat: illegal option -- -

The BSD derived stat command on these systems would use:

stat -f "%m"

It doesn't seem that we should have to test for what system things are on but should find a universally workable method.

[jbrauer]

quick work-around is to use --no-cache with drush 6.2 when the remote is BSD.

[weitzman]

Another quick workaround is to upgrade to master branch as the sql-syn implementation has been radically simplified.

[jbrauer]

@weitzman if I'm not mistaken though that has to be done on both sides? At least it didn't seem possible to be on drush 6 and master at once...

[weitzman]

I think the best we can do is to support Drush6 on one side and it will be a bit messy as Drush can't cleanup temp files and such. Probably best to have Drush7 on both sides, yes.