[bug] Could not distinguish staged or modified file when call `gis status`

[nqminhuit]

the ## from git status has a meaning:

• the first one is staged
• the second one is modified, not staged.

for example: git output from vanilla git:

## master...origin/master
M  text-1
 M text-2

from gis:

  ## master...origin/master
  M text-1
  M text-2

SHOULD:

  ## master...origin/master
  M  text-1
   M text-2

[nqminhuit]

solution: use the option --porcelain=v2 (https://git-scm.com/docs/git-status#_porcelain_format_version_2)

• can split by spaces safely
• can use different color on head and upstream branch
• can use different color on staged and unstage
• require git v2.11.4 (base on first change in document: https://git-scm.com/docs/git-status/2.11.4) or later