Vue 2.5.15 发布，大量 Bug 修复和重构

Vue 在 2.5.14 做了许多重构和Bug修复，在发布一天后又发布了 2.5.15 修复被发现的严重 Bug。

2.5.15 Bug Fixes

• do not traverse VNodes when regsitering dependencies 84a9a9d, closes #7786

2.5.14 Bug Fixes

• codegen: support filters with () in older browsers (#7545) dc97a39, closes #7545 #7544

• core: disable dependency collection in lifecycle hooks and data getter (#7596) 318f29f, closes #7596 #7573

• core: handle edge cases for functional component returning arrays 8335217, closes #7282

• inject: use hasOwn instead of 'in' for provideKey check (#7460) 733c1be, closes #7460 #7284

• model: fix array index binding for v-model checkbox (#7671) 550c3c0, closes #7671 #7670

• observer: do not invoke getters on initial observation (#7302) 7392dfc, closes #7302 #7280

• ref: allow ref key to be zero (#7676) e396eb3, closes #7676 #7669

• show: prevent transitions from starting on change truthy values (#7524) 013d980, closes #7524#7523

• types: contravariant generic default in ComponentOption (#7369) 6ee6849, closes #7369

•             fix ssr env detection in weex (#7375) 3eb37ac, closes #7375

• transition: should not add transition class when cancelled (#7391) 5191f13, closes #7391#7390

• types: add missing listeners type on RenderContext (#7584) db1b18c, closes #7584

• types: fix wrong errorCaptured type (#7712) 6b8516b, closes #7712

• types: make render option in functional components to optional (#7663) b2092db, closes #7663

• types: make VNodeChildrenArrayContents type more accurate (#7287) 49aae6b, closes #7287

• types: prefer normal component over functional one (#7687) 144bf5a, closes #7687

• v-model: handle trailing whitespaces in expression (#7737) db58493, closes #7737

• v-on: return handler value when using modifiers (#7704) 6bc75ca, closes #7704

• vdom: svg inside foreignObject should be rendered with correct namespace (fix #7330) (#7350) 0529961, closes #7330 #7350

• weex: default value for editor, fix #7165 (#7286) e055df8, closes #7165 #7286 #7165

• address potential regex backtrack cd33407

• allow codebase to be inlined directly in HTML (#7314) dccd182, closes #7314 #7298

• always install composition event listeners f7ca21e, closes #7367

• clean up custom events when patched component no longer have events d8b0838, closes #7294

• do not special case attributes for custom elements 50b711a, closes #6864 #6885

• fix config.productionTip ced00b1, closes #7565

• install ssr helpers for functional context during SSR 9b22d86, closes #7443 nuxt/nuxt.js#2565

• respect type order when boolean casting multi-typed props 81e1e47, closes #7485

• skip v-model & value binding collision check with dynamic type binding (#7406) 1c0b4af, closes #7406 #7404

• support KeyboardEvent.key in built-in keyboard event modifiers (#7121) 1c8e2e8, closes #7121#6900

• support v-model dynamic type binding for v-bind="object" 41838c8, closes #7296