Mark TaskCompletionSourceExtensions as preliminary for its first release as a publicly-exposed type
Merge pull request #54 from sharwell/preliminary

Mark TaskCompletionSourceExtensions as preliminary for its first release
Add missing documentation elements
Disable the ESENT cache since it can cause certain reference links to not be resolved
Remove unnecessary project references
Fix explicit documentation reference to System.Progress<T>
Fix issues with non-Roslyn compiler failing to resolve reference links
Add 'ReleaseNoDocs' solution configuration
Move documentation projects to their own solution folder
Expand PCL support to include Windows Phone 8.1 (fixes #55)
Merge pull request #56 from sharwell/fix-55

Expand PCL support to include Windows Phone 8.1
Merge pull request #57 from sharwell/doc-problems

Doc problems