Prepare for release 1.15.16 of R.NET

Fix https://rdotnet.codeplex.com/workitem/120

Commit to release 1.5.14, with a fix from @dcharbon for an issue that…

… appeared in Deedle

Update version, to create packages for an alternate channel for distr…

…ibution via NuGet

Commit to release 1.5.12

Merge for release 1.5.11

R.NET 1.5.10

Fix NuGet version dependency.

Fix namespace.

Fix test name.