Parsing files with ParseMode
Merge branch SearchSummary into master.

- Add auto-download of missing NuGet packages during build
- SearchSummary: add PDF file format, add displaying context, refactor the whole
  module
- Add "Export" button to the main form (plug the SearchSummary module into core)
fixing master branch -.-
fixing master branch 2
Remove .nuget/NuGet.exe