Added Outline Service classes and created tests for services_common
Added support for and tests for members and top level variables
Combined into root level OutlineEntry class.  Added range (start offset and end offset).  Switched fromMap constructors to populateFromMap() method
cleaned up and added docs
Moved test to test folder and enabled in all.dart.
Added copyright and extra line at EOF
Review fixes
Merge pull request #1214 from dart-lang/umop-outline-common

Outline common classes and tests