New Ft. for Git : Allow resumable cloning of repositories.

Objective: Allow pause and resume functionality while cloning repositories.

Below is a rough idea on how this may be achieved.

1) Create a repository_name.json file.
2) repository_name.json will be an index file containing list of all
the files in the repository with default status being "False".
   "False" status of a file signifies that this file is not yet fully
downloaded.

Something like this:

{
  'file1.ext' : "False",
  'file2.ext' : "False",
  'file3.ext' : "False"
}

3) As a file finishes downloading, say 'file1.ext' and 'file2.ext'
have finished downloading, their status will change to:

Something like this:

{
  'file1.ext' : "True",
  'file2.ext' : "True",
  'file3.ext' : "False"
}

4) Suppose due to some reason, before 'file3.ext' could finish
download; cloning is interrupted.
5) After the interruption the repository_name.json and downloaded
files are preserved.
6) Now, when cloning of the same repository begins next time, files
would be downloaded based on information taken from
repository_name.json file.

Note 1: Doing this for cloning would be the main objective, further this may be extended for fetching, pulling, and pushing too.

Note 2: Since this is gsoc time, please don't take this to be a project idea for gsoc, as it was pointed out on irc that this would be a time intensive functionality.

I want to work on building this functionality. Please discuss thoughts on this, so as to make a technically sound to-do list.