Merge branch 'ls/p4-lfs'

Merge branch 'ls/p4-lfs'

Teach "git p4" to send large blobs outside the repository by
talking to Git LFS.

* ls/p4-lfs:
  git-p4: add Git LFS backend for large file system
  git-p4: add support for large file systems
  git-p4: check free space during streaming
  git-p4: add file streaming progress in verbose mode
  git-p4: return an empty list if a list config has no values
  git-p4: add gitConfigInt reader
  git-p4: add optional type specifier to gitConfig reader