There were multiple threads started on ST forums, I will post a few of them where you may find suggestions that may help, but there are no ways to do this but keeping the path relative to the .sublime-project
file. You may keep it in the directory where your project resides and point to it with "path": "."
.
https://www.sublimetext.com/forum/viewtopic.php?f=2&t=14601 http://www.sublimetext.com/forum/viewtopic.php?f=2&p=57728 https://www.sublimetext.com/forum/viewtopic.php?f=2&t=15278
As ST devs are very quiet right now I doubt it will be changed before the ST3 release.