Merge pull request #4 from dnnsoftware/development

rollback https://github.com/dnnsoftware/Dnn.Platform/pull/162 as it is c...
DNN-5874 Check if unique display name is required when changing display name
[DNN-6037]

Updated HtmlTextController.cs, ManageRelativePaths() to skip tags with
"data:image" in the src property.  As the calling method
(FormatHtmlText) also hard codes the search for "src" and "background",
and the Data URI Scheme has been integrated in HTML since version 4.01,
it seems safe to allow the hard coding.  A potential improvement could
be to also allow "data:text/csv". This fix only applies to most non-IE
browsers.  IE doesn't send the base64 data when drag/drop is utilized,
so this fix also doesn't positively or negatively affect IE users.
Solution is simpler and cleaner than that suggested in DNN-6037.
Fixed DNN-6061: Tab "Purchased Extensions" now shows all available download files for a product
DNN-6077 HtmlUtils methods should accept null strings

Added check for null or empty strings to all methods (except StripEntities, as it marked obsolete). If null or empty string is passed, modified methods return it unchanged.
Refactoring and minor performance improvement in DotNetNuke.Common.ProcessHttpModule
DNN-6125 truefalse control not saving unchecked state
DNN-5503: added dismiss all notifications feature.
DNN-6024 Don't default link manager to https:// when SSL is enabled

Instead, update the AbsoluteToRelativeUrls method to ignore the protocol.

Reverts some of 9703902883c289717e9ea926fd7e5f6610e2a8e2
Fixing faulty rendering of properties with spacial chars in it.
DNN-5503: some QA requested changes for dismiss all notifications feature.
DNN-6137 Multilanguage support for site settings
DNN-6143 - the CDV added to the profile picture URL is now based on its last modification date
DNN-6138 Upgrades fail if PortalSettings include empty CultureCode
Added code in the 7.4.0 SQL script to convert empty strings to nulls
Merge pull request #185 from janjonas/DNN-6061

Fixed DNN-6061: Tab "Purchased Extensions" now shows all available download files for a product
Merge branch 'development' of https://github.com/dnnsoftware/Dnn.Platform into development
Merge pull request #197 from janjonas/DNN-6098_2

DNN-6098: Refactoring and minor performance improvement in DotNetNuke.Common.ProcessHttpModule
DNN-5943 + CONTENT-3590 - An error during notification sending does not stop the workflow process
DNN-5943 + CONTENT-3297 - Versioning and Workflow API documentation
Merge pull request #203 from peppertree/DNN-6125

DNN-6125 truefalse control not saving unchecked state