ProjectLayout is not sealed anymore
You can't know all final number of possible
project layouts, so let users implement their own, if needed.
Mention implicits and proguard cache interaction
Merge pull request #89 from dant3/project_layouts

ProjectLayout shouldn't be sealed
Don't restrict proguard-cache to scala-only
0.13 changes
0.13 changes for 0.9.2
0.13 changes for test hello-world-oscarvarto
0.13.5 changes
fix #65 add AutoPlugin support, auto-enable with AutoBuild
Add aliases for AutoPlugin autoImport

aliases added for ProguardCache, ProguardInputs, apklib, aar,
AutoLibraryProject and LibraryProject
Try to disable automatic plugin enablement...
Change autoImport to be Keys directly
create a new test case for #60, unable to repro
Add language.implicitConversions to Keys