ctx: protect against nil mgr
worker: disallow ctx.Svc(n) during event-loop
all: first stab at a job scripting interface
fwk/job: general support for (de)serialization of job.Stmts
job/stmt: implement Stringer
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