'git lfs track' now automatically touches matching files already in git
'git lfs track' now automatically touches matching files already in git

This makes them appear as modified in 'git status' which indicates they
need to be re-committed to be moved into LFS if already in git.
See #1057

aleb/git-lfs,github/git-lfs,dakotahawkins/git-lfs,aleb/git-lfs,ttaylorr/git-lfs,bozaro/git-lfs,aleb/git-lfs,github/git-lfs,Jericho25/-git-lfs_miilkyway,ttaylorr/git-lfs,dakotahawkins/git-lfs,Jericho25/-git-lfs_miilkyway,larsxschneider/git-lfs,Jericho25/-git-lfs_miilkyway,github/git-lfs,andyneff/git-lfs,dakotahawkins/git-lfs,andyneff/git-lfs,bozaro/git-lfs,larsxschneider/git-lfs,andyneff/git-lfs,larsxschneider/git-lfs,ttaylorr/git-lfs,bozaro/git-lfs