Suggestion: group files in GIT

I would like to group some files, so I can list group files together, list group changes together, filter by group for staging, also order by group. It seems, there is no such feature in GIT I would need, so I send it as suggestion.

We can call this feature as "Group files" or "Label files" (labeling is used in Gmail, so this may be also a naming alternative).

Example file list I would like to group together into [group1]: theme/header.php theme/footer.php theme/body.php lib/theme.php

They are in different directories, but mostly belongs together, so if I group them, then I can work easier with them.

- I could select a file group for staging, so only the changes in the
group would be added to stage. Changed files in the group:
[group1]/theme/header.php
[group1]/lib/theme.php

- I could list files filtered by a group. Files filtered by [group1]:
[group1]/theme/header.php
[group1]/theme/footer.php
[group1]/theme/body.php
[group1]/lib/theme.php

- I could order file list to list group files first, then directory files.
[group1]/theme/header.php
[group1]/theme/footer.php
[group1]/theme/body.php
[group1]/lib/theme.php
other/files.php

I listed just a few basic cases, when grouping/labeling could be useful, but there may be more.

Please consider implementing this feature into GIT.

Thanks, Konrad Lorinczi