Releases for RedHen Membership

Changes since 7.x-1.0-alpha1:

• Normalizing line length in README.
• #1679808 by nedjo: Define approach to handling role id, which can break on export to features.
• Ignore empty start/expire dates during validation
• Fix variable by reference error in RedhenMembership::label().
• Changing membership start and expire dates to use int time fields rather than timestamps to make the values easier to integrate with Views et al.
• Use renamed hook_redhen_contact_user_update()