Patch to compile less when minifying files
[#3023] Add new extension points to pass the package dict

When creating or updating a dataset, extensions can hook to the
`after_create` and `after_update` methods to receive the validated data
dict. In the create case, the id is added to the dict.
Merge branch 'master' into 3023-data_dict-extension-points
[#3023] Pass context object to extensions on after_create and after_update
[#3023] Add new after_show extension point

Gets the package dict just before being sent back to the controller.
Removed an out of date comment on tests.
[#3028] Add `followee_list` and `followee_count` action functions
[#3028] Add search filtering to followee_list
[#3028] Change format of dicts returned by followee_list

Match the format requested by @johnmartin for the frontend
[#3028] Refactor a couple of activity streams methods

Refactor _activites_from_users_followed_by_user_query() and
_activites_from_datsets_followed_by_user_query(), make them use an
SQLAlchemy union of _user_activity_query() for all users followed by the
given user and _package_activity_query() for all datasets followed by
the given user, respectively.

This just ensures that what appears in a user's public activity stream,
for example, is exactly what will appear in your dashboard activity
stream if you follow that user. Better than having two different
implementations of the SQL for this query.

_activites_from_groups_followed_by_user_query() already works this way.
[#3028] Fix a mistake in followee_list
[#3028] Document an undocumented param
[#3028] Update a comment
[#3028] Fix a docstring
[#3028] Dashboard now shows dropdown for filtering of activity stream

Still todo:

* Add header for context of specific item active within dropdown
* Snippetize the followee list
* Searching the dropdown (with JS enabled)
[#3028] Snippetized followee dropdown and added context to dashboard when filtering
[#3028] Followee dropdown on dashboard is now searchable via ajax
[#3028] Related context now has better arrow from right hand side
[#3028] My datasets on dashboard now look's nice
[#3028] Small tweak to user dropdown in header
[#3028] Added some doc blocks