Updated to use the new AppContext contract
- ApplicationContext was renamed to AppContext
Missed one place
Rename IApplicationEnvironment.TargetFramework to RuntimeFramework
Ignore unit tests temporarily to make KRuntime build
Bring back unit tests
Add 'webroot' property to project.json
Add '--wwwroot' and '--wwwroot-out' option to "kpm pack"

- '--wwwroot' specifies the name of public folder in project dir
- '--wwwroot-out' specifies the name of public folder in packed image
- '--appfolder' is replaced by '--wwwroot-out'
- If '--wwwroot-out' is not specified, the packed image doesn't contain a public
  folder
Code review changes
Add interaction between "kpm pack" and 'webroot' property of project.json