Add install and upgrade information for CentOS/RHEL and Ubuntu
Merge pull request #2166 from opf/hotfix/update_docs_supported_distros

Add install and upgrade information for CentOS/RHEL and Ubuntu
Make the installation prerequisites more consistent with regard to CentOS/RHEL, Fedora and Ubuntu
formatting of bullets
rewriting i18n tests as specs
one class variable less
Merge pull request #2165 from opf/hotfix/i18n_testing_as_specs
Fix the URL for the stable branch of Fedora 20 packager
Merge pull request #2172 from lindenthal/release/4.0

Fix the URL for the stable branch of Fedora 20 packager
Fix config_files paths in Hound config
Correct API experimental's users path
Merge pull request #2177 from opf/hotfix/17173_user_related_wp_filters_are_inactive

17173 User related WP filters are inactive
allow nested config env override and addition of new values
don't hardcode ENV as source for config override
Add jshint-stylish, configure as JSHint reporter

Signed-off-by: Alex Coles <alex@alexbcoles.com>
more flexible prefix
make sure to only replace an actual prefix
Treat zero as not null
editable description support
Merge pull request #2106 from 0xF013/feature/16988-editable-description