misc/docker-setup: configuring git to never use git protocol

We use https instead. This configuration enable anyone clone
repositories behind a proxy that disables the use of git protocol.
misc/proxy-setup: prompting for proxy configurations on docker install
docker-setup: s/docker-master/docker-latest/; # oops, missed one after testing
misc/hipache-router: keeping environment variables when running npm with sudo

This will maintain any proxy settings from the current user.
Merge pull request #481 from dgryski/fix-docker-latest-again-oops

docker-setup: s/docker-master/docker-latest/; # oops, missed one after t...
misc: moving proxy settings to execute first than other scripts

Also setting npm proxy inside hipache setup script.
misc/docker-setup: created function that downloads scripts if they do not exists
misc/proxy-setup: fixing typo
misc/docker-setup: changing mode of downloaded files
misc/proxy-setup: fixed use of existent shell(or bash) set function
docs/docker.rst: updating docker install docs to other install files if are not present
gandalf-setup; 'sudo su - user' is redundant.

Use 'sudo -u user -i' instead.
gandalf-setup: make sure .ssh exists, or 'key-add' will fail.

Arguably gandalf should check this itself in user/key.go:writeKey()
misc/proxy-setup: sourcing /etc/profile after writing proxy conf on it
misc/docker-setup: fixing hipache setup file name

Also changing the actual file name to follow the standard
misc/docker-setup: passing -E flag to sudo in curl so we maintain proxy envs

Also commented tsuru automatic startup and warning the user of
additional configurations he/she still need to do by hand.
misc/proxy-setup: removed old comment
Merge pull request #483 from dgryski/gandalf-setup-fixes

Gandalf setup fixes
docs: improved api docs.
docs/api: added sections for all 'endpoints'.