Use argv0 as reexec implementation for dockerinit

This changes the way the exec drivers work by not specifing a -driver
flag on reexec.  For each of the exec  drivers they register their own
functions that will be matched aginst the argv 0 on exec and called if
they match.

This also allows any functionality to be added to docker so that the
binary can be reexec'd and any type of function can be called.  I moved
the flag parsing on docker exec to the specific initializers so that the
implementations do not bleed into one another.  This also allows for
more flexability within reexec initializers to specify their own flags
and options.

Signed-off-by: Michael Crosby <michael@docker.com>
Remove unsued sysinit package

Signed-off-by: Michael Crosby <michael@docker.com>
Fix hack in old integration test for new init

Signed-off-by: Michael Crosby <michael@docker.com>
Add test case for identical short and long version numbers

Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com>
Fix equal short-long version number comparison

Signed-off-by: Lajos Papp <lajos.papp@sequenceiq.com>
Private Repos Copy Change

Docker-DCO-1.1-Signed-off-by: Christopher Biscardi <biscarch@sketcht.com> (github: ChristopherBiscardi)
Remove Old shiftWindow()

closes #7493

Docker-DCO-1.1-Signed-off-by: Christopher Biscardi <biscarch@sketcht.com> (github: ChristopherBiscardi)
Panic if trying to register an func with the same name

Signed-off-by: Michael Crosby <michael@docker.com>
Merge pull request #7490 from crosbymichael/reexec

Use argv0 as reexec implementation for dockerinit
Updates docs regarding linux mint troubleshot

Signed-off-by: Ciro S. Costa <ciro.costa@usp.br>
Move TestRunWorkdirExistsAndIsFile to integration-cli

Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com>
Move TestRunExit to integration-cli

Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com>
Merge pull request #7533 from cirocosta/patch-1

Updates docs regarding linux mint troubleshot
Merge pull request #7531 from ChristopherBiscardi/priv-repos

Private Repos Copy Change
Merge pull request #7528 from lalyos/fix_version_number_comparison

Fix version number comparison
Add irc-meetings section in CONTRIBUTING

Signed-off-by: Tibor Vass <teabee89@gmail.com>
Merge pull request #7466 from tiborvass/irc-meetings

Add irc-meetings section in CONTRIBUTING
Fix my email entry so that my current email is first and the old commit email second.

Docker-DCO-1.1-Signed-off-by: Andy Rothfusz <github@developersupport.net> (github: metalivedev)
Add process for PR acceptance, review, rejection

This is an extremely tentative PR.  However, I feel that the suggestions are generally good.

Docker-DCO-1.1-Signed-off-by: Timothy Hobbs <timothyhobbs@seznam.cz> (github: timthelion)
Merge pull request #7538 from LK4D4/move_some_integration_to_cli

Move some integration to cli