m_identity: don't crash if #identity_password_match{} doesn't match any observers.

(cherry picked from commit 410c11c6cb5b99a2fe258451b66ca2da98965fdd)
core: add lager warnings when modules are stopped.

(cherry picked from commit 06301f1eb0e7c57fbcbec2d9e4c1480620593434)
core: lager info with modules to be started.

(cherry picked from commit 82afbc72f4dc3ce1e25ccd43804ad56b161a15d8)
mod_tkvstore: don't start as named module.

(cherry picked from commit 3604d7c8e467fdf8a720f376fea67e9ab6b137eb)