add: Piwik support
fix: PIWIK_URL sed delimiter
Merge branch 'ziirish-master'
dockerfile: upgrade to sameersbn/ubuntu:14.04.20141218
changelog: updated
gitlab-shell: upgrade to v.2.4.0
gitlab: upgrade to CE v.7.6.0
Merge branch 'gitlab-next'
release 7.6.0
Disable IPv6 support for Nginx

On some servers, IPv6 is not available, so Nginx can't listen on  [::]:80 

	2014/12/19 07:18:32 [emerg] 484#0: socket() [::]:80 failed (97: Address family not supported by protocol)

I removed the line and the container start successfully.
Merge branch 'ahmet2mir-patch-1'
Disable IPv6 for SSL as well
init: added GITLAB_BACKUP_TIME configuration option

Refer #77
gitlab: upgrade to CE v.7.6.1
release 7.6.1