DNN-4755, Allow for more tokens in CoreMessaging E-Mails

As described in the ticket; this will allow for more tokens and therefor
greater flexibility in the core messagin template. It's just adding a
few more tokens with no impact on anything else.
Improved Tokenreplce
DNN-5601 Allow specifying null type to GetValue and GetValueOrDefault
Fix DNN-5629: RoleController.DeleteRole() now removes UserInfo objects from data cache as they have been modified
DNN-5361 Config manager upload button always active
Add code documentation in AJAX.cs
CONTENT-2698 - Set DotNetNuke.Library AssemblyInfo status in ReleaseMode.Stable
DNN-5649 improve captcha logic
DNN-5649 improve captcha logic
DNN-5687 User account settings are not applied at host user accounts
DNN-5671 Message on Languages module reads "DotNetNuke"
correct message
When only [Cacheable] is used without any addtional attributes, the system defaults to a timeout and priority of zero, which doesn't work all that great.
reduce calls to sql for non-existent users
[DNN-5628] Fixed hydration bug found in Social  -fixed bug with typo in script name (contributed by Sebastian Leupold)
[DNN-5628] Fixed hydration bug found in Social  -fixed bug with typo in script name (contributed by Sebastian Leupold)
DNN-5648 Upgrade wizard modified to support override of the version label
DNN-5710: fixed failing search unit tests.
DNN-5722 Portal Creation notification mechanism
Merge branch 'release/7.3.2' into development