made scala sdk provided
exclude fixes

Testing Done:
some tests are failing while trying to find a Scala class in the output. it's failing even without my changes. waiting for Pants OSS CI before trying to run our ci.

in the mean time trying to investgate why it's not working locally.

Reviewed at https://rbcommons.com/s/twitter/r/1418/
Running integration tests without coping huge projects

Testing Done:
https://travis-ci.org/pantsbuild/intellij-pants-plugin/builds/43050689

Reviewed at https://rbcommons.com/s/twitter/r/1431/
Use target address as external.linked.project.id for a module

Testing Done:
https://travis-ci.org/pantsbuild/intellij-pants-plugin/builds/43059330

Reviewed at https://rbcommons.com/s/twitter/r/1433/
replace comments w/ methods in PantsResolver#addInfoTo; change keySet/get to entrySet

Testing Done:
Tests pass locally.

Reviewed at https://rbcommons.com/s/twitter/r/1436/
Changes + inc since-build to be compatible with the latest Scala plugin
Add sources
merge from master
Revert iml