[RFC] separate .git from working directory

["Nguyen Thai Ngoc Duy" <pclouds@gmail.com>]

Hi,
I was thinking about this while reading subproject thread. In a simple
case, I have a repo A located at ~/project-a and another repo B
located at ~/project-a/some/dir/project-b. With this setup, command
"find" and other directory-recursive commands will run horribly from
~/project-a when they go inside project-b/.git (no I don't want to
repack -d everytime I want to find something).
I propose to move project-b/.git outside and place a file, say
.gitdir, in project-b directory. git-sh-setup and setup_git_directory
are taught to recognize .gitdir, read it to find the actual GIT_DIR
recorded inside .gitdir. This way git commands inside project-b should
work fine while I can "find ~/project-a -name blah" or "grep -R blah"
quickly.
.gitdir format could be  a simple shell-like format with environment
variable assignments.
BTW, talking about subproject support, how about git be taught to
ignore directories which contain .gitdir so that git commands will not
waste time checking project-b directory?
-- 
Duy