Include NDK_PROJECT_PATH in env

This seems necessary for ndkBuild with jni sources under src/main.
Merge pull request #82 from mrdomino/master

Include NDK_PROJECT_PATH in env
fix #87 change aapt processing message
fix 84 and fix #85 depend on managedResources and sourceManaged fix
fix NDK_PROJECT_PATH for all layouts #82
adjust location of .h check because gen=sourcemanaged (#85)
Add jni libraries to list of dependencies for apkbuild
1.3.4 release
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