Initial implementation of virtual nodes
Fixes for virtual nodes and initial perf test class

Introduced a dependency on an extension to dotNetRDF to enable VNodes to
perform better. So this feature branch will remain open until DNR is
officially updated.
Updated DNR to 1.0.5
Update version number and whats new
Fix DNR dependency to 1.0.4
Update installer readme and fix nuspec typo
Fixed NancyFX razor configuration
Fix for error during consolidate job

Issue #130
Use round-trip format for Double and Single values

Issue #98
Upgrade core.sln to DNR 1.0.6
Merge branch 'release/1.7' into develop
Merged branch feature/virtual_nodes