bp_ass_activity_notification_message filter should create user-specific message variable

It was wiping out the un-user-specific $message, which was causing user-
specific footer info to be appended over and over again during the group loop.

See fd6965a056539
ensure no double footer in notifications
Merge pull request #57 from christianwach/footer

Ensure no double footer in notifications.

Commit d2c9ec3 affected legacy forum content.  We also need to fix activity-based content.
Allow plugins to filter the redirect URL for ass_get_login_redirect_url().

This commit:
- Adds a second parameter to ass_get_login_redirect_url() to denote the
  context of the redirect
- Adds a new filter in ass_get_login_redirect_url() - 'ass_login_redirect_to'
  so plugins can modify the redirect_to URL

See #54.
Add new phpDoc for ass_get_login_redirect_url().

See #54, commit 4c86bd0.
Fix notice generated by bbPress when a forum post is submitted.

bbPress 2.5.4 changed the way emails are sent out and broke a filter that
GES was using.  bbP 2.5.4 now sends out one email to topic subscribers and
BCCs everyone that is subscribed to that topic.

For bbPress 2.5.4, this commit filters the list of topic subscribers and
removes the subscriber from the list if the subscriber is already
subscribed to the group's "All Mail" option in GES.  This is done to
prevent duplicate emails.

Fixes #59.
Fix potential empty activity ID being set during digests.

See https://wordpress.org/support/topic/wordpress-database-error-misplaced-comma

Props @tomdxw
Filter Nav Item Visibility

Allows developers to easily hide the tab if not needed.
Merge pull request #62 from dcavins/filter-nav-tab-visibility

Filter Nav Item Visibility
Switch to on() for JS event delegation, rather than deprecated live()

Fixes #63

Props @mecanographik for an initial patch
Readme
Pass `$group_id` to `display()` in group extension class.

This is to avoid strict standards warnings in BP 2.2.
Readme update.
Bump version numbers to 3.5
Update POT file for 3.5.
check if bbPress function exists before calling it
Merge branch 'bbpress-check' of github.com:christianwach/buddypress-group-email-subscription into bbpress-check