vcsh: Make status show commits ahead/behind remote

This is work in progress:
* It does not deal with repos without a remote tracking branch
* It does not share any info if run on a single repo
* I should probably factor this out in a new function

github: in response to richih/vcsh#123
Fix format string vulnerabilities

Never pass user input as first argument of printf(1),
similar to how you never do that with printf(3).

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>
Display full paths in list-tracked*

Closes https://github.com/RichiH/vcsh/issues/125

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>
typo: "availabile.d" to "available.d"
Merge pull request #135 from ajschumacher/patch-1

typo: "availabile.d" to "available.d"
Merge pull request #134 from mirabilos/master

fix issue 125 and some printf vulnerabilities
Makefile: Allow `PREFIX=foo make install`
typo `that you cat track` -> `that you can track`
Merge pull request #138 from yuvallanger/patch-1

typo `that you cat track` -> `that you can track`
Rename `foo` to a meaningful name `repo_name`

I get lost within all of those meaningless names.
It is useful to give things meaningful names, especially in documentation.
Merge pull request #139 from yuvallanger/patch-2

README: Using a `repo_name` instead of `foo`
Release v1.20141009
test commit
test commit
test commit; rewrite to use comm and two temp files to get around argument too long crap
3rd try
vcsh: Make `vcsh which dontexist` exit 1

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=760882
vcsh: Add support for overlay functions
Force temporary file/directory removal
Add checks to file operations