Move Unicorn unix socket out of /tmp

Fix gl-setup PATH warning when executing gl-system-install.

My git user uses bash (so .bash_profile), but I think it should work the same for sh shell.

Full warning message:

                ***** WARNING *****
gl-setup is not in your $PATH.

Since gl-setup MUST be run from the PATH (and not as src/gl-setup or such),
you must fix this before running gl-setup.  The simplest way is to add

    PATH=/home/git/bin:$PATH

to the end of your bashrc or similar file.  You can even simply run that
command manually each time you log in and want to run a gitolite command.

Run /home/git/gitolite/src/gl-system-install -h for a detailed usage message.

Automagically fills the email on add ssh key page

- when you add a new ssh key, the title field automatically fills with the email (if is present in the key sting)

added nginx access_log; error_log directives for easier debugging vhost ...

added proxy_set_header directives to prevent "ssl_error_rx_record_too_long"
added subdomain "gitlab.YOUR_SUBDOMAIN.com" to server_name directive
added "YOUR_SERVER_IP" to listen directive

Move OmniAuth configuration details into a non-revision controlled file.

Ensure LDAP provided email is always compared case-insensitively.

Useful for Sqlite or Postgres installations.

Changed for mysql2 adapter