update header
Merge branch 'master' into dev
remove duplicated build file.
add win/*nix build batch file.
update readme file.
upgrade packages.
remove header.
Merge branch 'cleanup' into dev
new domain.
add new structure.
structure  adjustment and new classes.
more details for Paper, Exam, Question.
lots of changes.
new project Oas.
fix packages.
asp.net identity.
add connection string for membership.
clean up service interface.
implemented home/index
adjust controller logic.