reorganize tests, with clean workspace and repeatability

using WorkspaceTest as base class for tests
restrict exported guava packages
small fix in ErlParser
pathVars: use project's resolver

this allows using predefined vars like PROJECT_LOC
cleanup OtpRpcFactory
removed unused OpenService.getExternalInclude
merge ModelSearcherService into ModelFindService
extract Util.asStringList
small fixes
code cleanup