Update presentation style reference for the latest release of SHFB
Improve documentation build performance by only producing website output
Enable the Version Builder plugin for the netcore45 output (for publication)
Add features overview to User Guide
Fix dependencies for everything except .NET 3.5 (fixes #2)
Merge pull request #3 from sharwell/documentation

Documentation updates
Merge pull request #4 from sharwell/fix-2

Fix dependencies for everything except .NET 3.5 (fixes #2)