[GSoC][PATCH v2 0/4] submodule: Incremental rewrite of git-submodules

Changes in v2:

* In the function get_submodule_displaypath(), I tried avoiding the extra
  memory allocation, but it rather invoked test 5 from
  t7406-submodule-update. The details of the test failiure can be seen
  in the build report as well. (Build #162)
  This failure occured as even though the function relative_path(),
  returned the value correctly, NULL was stored in sb.buf
  Hence currently the function is still using the old way of
  allocating extra memory and releasing the strbuf first, and return
  the extra allocated memory.
* It was observed that strbuf_reset was being done just before the strbuf
  was being reused. It made more sense to reset them just after their use 
  instead. Hence, these function calls of strbuf_reset() were moved
  accordingly.
  (The above change was limited to the function init_submodule() only,
   since already there was a deletion of one such funciton call,
   and IMO, it won't be suitable to carryout the operation for the complete
   file in the same commit.)
* The function name for_each_submodule_list() was changed to
  for_each_submodule().
* Instead of passing the complete list to the function for_each_submodule(),
  only its pointer is passed to avoid the compiler from making copy of the
  list, and to make the code more efficient.
* The function names of print_name_rev() and get_name_rev() were changed
  to get_rev_name() and compute_rev_name(). Now the function get_rev_name()
  acts as the front end of the subcommand and calls the function
  compute_rev_name() for generating and receiving the value of revision name.
* The above change was also accompanied by the change in names of some
  variables used internally in the functions.

As before you can find this series at: https://github.com/pratham-pc/git/commits/week-14-1

And the build report is available at: 
https://travis-ci.org/pratham-pc/git/builds/
Branch: week-14-1
Build #163

Prathamesh Chavan (4):
  submodule--helper: introduce get_submodule_displaypath()
  submodule--helper: introduce for_each_submodule()
  submodule: port set_name_rev() from shell to C
  submodule: port submodule subcommand 'status' from shell to C

 builtin/submodule--helper.c | 294 ++++++++++++++++++++++++++++++++++++++++----
 git-submodule.sh            |  61 +--------
 2 files changed, 273 insertions(+), 82 deletions(-)