Allows use of CKAN_INI env-var to locate config

Implements #1597

If you don't specify a config file using the -c option, CKAN defaults to
looking for development.ini in the current directory. This patch will
first check the -c parameter, and if it doesn't find it will use the
content of the CKAN_INI environment variable. If it cannot find that,
it will then default to development.ini in the current directory.
CHange error message, hope travis retests
[#2035] Refactor new_authz.check_config_permission to not cache things

Otherwise the values can not be overriden from tests
[#2035] Remove uneeded calls to clear_auth_functions_cache()
[#2035] Fix old auth tests
[#2035] Further fixes to auth tests

The old auth tests are terrible in that they depend on each other to
run. Also the auth cache thing masked some bad assumptions.

The whole file should be rewritten as new tests.
[#2035] Don't use http://foo.bar as a test url

Because `.bar` is being recognized as a gTLD, it points to
`127.0.53.53`, which if you have a web server running will return
localhost (and a 200 status).

More details:

https://stackoverflow.com/questions/25662590/domain-foo-bar-points-127-0-53-53-why
[#1597] Refactored for code clarity and improved error message.
[#2035] Improve non-existent URL added on 7d30f7c
[#2035] Split all whitespace when parsing roles_that_cascade_to_sub_groups

Use split() rather than split(' ')
2054-fix meta property og:description

fixes #2054 by trimming whitespace
Merge pull request #2055 from jqnatividad/master

2054-fix meta property og:description
Merge pull request #2005 from ckan/1597-config

Allows use of CKAN_INI env-var to locate config
Merge branch '2035-remove-auth-permissions-cache'
[#1941] More concise way to ensure HttpOnly
[#1941] Warn against setting httponly to False
[#1941] Tweak changelog for CORS and HttpOnly
Merge branch 'brew-1941-httponly'
Merge branch 'master' of github.com:ckan/ckan
Merge branch 'master'into 1942-secure-cookie