invite 5.x-1.9

Hotfix release. Do NOT use the original 1.8 release.

Note: Invite 1.8 requires you to have the token module installed.

Changelog from 1.9:
Bugs fixed:
- #161829: Blank sender on invite email.
- Prevent emails from looking like spam to SPF-enabled MTAs.
- Fixed sending invites for anonymous users (they don't have an email address).

Changelog from 1.8:
New features:
- #157494 by MarcoR: Show message preview to inviting user.
- #120248: Added token support.
- #100360: Added an invite block.
- #151617 by knseibert, smk-ka: Display only roles on the settings page which have "send invitations" permission set. Only take those into account when escalating the roles for the invitees and checking the send limitations.
- #160969: Delete invite when a user is deleted. To prevent fraud, this will only happen when "Allow deletion of joined users" is enabled.
- #145271 by thierry_gd: Added hook_uninstall().
- #134867 Auto-approve invited users' accounts.
- Added hook_disable().
- Added customizable email subject.
- Got rid of the disabled form in case the invitations limit was hit by redirecting to the new invitation listing page.
- Added Italian translation, contributed by Mr.Bittertooth.

Bugs fixed:
- #137495: Notifing other modules of role change.
- #143373: Don't escape quotation marks and other special characters in plain text e-mails.
- #135345 BLOB/TEXT column 'message' can't have a default value (MySQL 5).
- Fixed From and Reply-To header generation.
- Check that there is at least one valid email remaining after filtering out dupes to prevent the form from resetting.