Remove overriding settings from LabelTypeIT setUp so that those tests
assume defaults defined in LabelType (and exercised in ProjectConfig).
Add initialization of such defaults to LabelType constructor; otherwise,
defaults set to true were not initialized as such, served false instead.
Add mentions of false defaults to Documentation, for copyMinScore and
copyMaxScore (used to be missing). Only allProjects had its copyMinScore
default set to true, in AllProjectsCreator (initCodeReviewLabel).
Change-Id: I7957ff8d628d7e1744a910e66dcae6b41343a7e7
5f834717cc