Publish: Tweaked ImplementationUtils
Renamed interface.xsl|css to feed.xsl|css
SolverRun: Extracted logic to SelectionCandidateProvider and merged rest into BacktrackingSolverRun
0install add-feed: fixed exception on empty <feed-for>s
Avoid string concatenation and boxing for implicit .ToString()
Avoid boxing of enums
Minor tweaks and cleanups
Model: Turned VersionPart and VersionDottedList into structs
Added support for template variables in ImplementationVersion and Released
Publish.WinForms: Added .xml.template to known filters
Updated dependency: Newtonsoft.Json
Added ReSharper team-shared settings
Fixed handling of version restrictions on <runner>s

- Tweaked Restriction.Normalize()
- Fixed Runner.Clone()
- Fixed Command.Normalize()
SecureStore: Tweaked event log access (avoid creating log entries longer that 32k)
Redesigned FlagUtils and RecipeUtils to handle directory renames
Use FeedUtils.Encoding everywhere
Tweaked cleanup.cmd
Updated SharpZipLib

Fixes manifest digest mismatches
Updated NanoByte.Common
Sign feeds in-memory

closes #81