mod_base: let contoller_page ignore query args and language on page_path check.
This also adds a new query arg  which contains the list of path-parts used for checking the dispatch rules.
Issue #746
mod_base: also let controller_page append qs on page_path redirect.
Fixes #746
core: prevent image-url checksum if only mediaclass defined.
This fixes a problem where a checksum was generated if an undefined width/height was specified, typically in a {% media %}
doc: Fix typos in if_undefined filter

Fixes #688
mod_admin_category: Add dependency to mod_menu

And update documentation which explains this dependency.

Fixes #670
skel: Remove unused controller_default_postcomment controller

Fixes #656
doc: Document the implicit variables which are always available in a
template

Fixes #541
docs: some more magic query args.
Issue #541
Replace OAuth implementation with a more recent one

We now use https://github.com/tim/erlang-oauth/. Since it is just one
file, oauth.erl, the file has been added to the support/ folder of
mod_oauth, instead of making it a sub-dependency.

Fixes #730
mod_base: Fix infinite loop in controller_page

When the resource had its page path set to "/", the calculation of the
request page path would fail, causing a redirect.
skel: Fix blog styling of navigation bar
build: Dont send Travis CI success notifications when it did not fail
install: Fix query syntax error due to missing comma
mod_survey: Work around mod_survey initialization error

Prevent database deadlock by doing the queries async after a delay. Not
the most beautiful solution, but it appears to work.

Fixes #734

See issue #497 for the discussion on the "proper" solution.
mod_survey: Add comment about schema initialization workaround
mod_survey: Slightly better workaround for survey initialization deadlock

no spawn or delay, just use a clean DB connection.
doc: remove stray doc file for unnamed template.
doc: add minimum description of mod_admin_stats.
doc: Add minimal documentation for mod_export

Fixes #724
core: Calculate a checksum instead of using a timestamp. Fixes #633