Revert "LoadProperty now converts null strings to empty"

This reverts commit a612379a4548c4d102457b9dfe92e7fa48f708ea.
Merge pull request #124 from BradRem/master

Reverting changes to LoadProperty converting null string to empty, closes #110
Merge pull request #125 from rockfordlhotka/master

Closes #123, update to latest nuget packages for async
Closes #126 Version 4.5.24 RC release
Merge pull request #11 from MarimerLLC/master

Update to 4.5.24 RC