job: introduce (*Job).setProp so Stmts are not added twice
test: test fwk/job.Stmt
fwk/job: split StmtCreate into StmtCreate and StmtNewApp
testdata: add a dummy property to svc1
fwk/job/gocodec: first import
job/gocodec_test: first import
job/gocodec: more thorough impl. + tests
testdata: add 'Struct' property to svc1