deps: update v8_inspector

To add a LICENSE file along with the v8_inspector code, we need to
pick up v8_inspector from an intermediate repository:
https://github.com/pavelfeldman/v8_inspector. This repo still tracks
upstream code in Blink.

This roll also picks up the latest v8_inspector from upstream fixing
a few issues.

* Pickup commit id bc60957 from pavelfeldman/v8_inspector
* Update node.gyp to adapt to the new file paths
* Update the DevTools hash for the devtools frontend.

Fixes: nodejs#7123
Fixes: nodejs#7736
Fixes: nodejs#7734

deps/v8_inspector/README.md

@@ -1,10 +1,10 @@
 V8 Inspector support for Node.js
 ================================
 
-This directory is a gathering of dependencies for Node.js support for the
-[Chrome Debug Protocol][https://developer.chrome.com/devtools/docs/debugger-protocol].
+This repository is an intermediate repository that gathers the dependencies for
+Node.js support for the [Chrome Debug Protocol][https://developer.chrome.com/devtools/docs/debugger-protocol].
 
-* platform/v8_inspector: vendored from https://chromium.googlesource.com/chromium/src/third_party/WebKit/Source/platform/v8_inspector
-* platform/inspector_protocol: vendored from https://chromium.googlesource.com/chromium/src/third_party/WebKit/Source/platform/inspector_protocol
-* deps/jinja2: vendored from https://github.com/mitsuhiko/jinja2
-* deps/markupsafe: vendored from https://github.com/mitsuhiko/markupsafe
+* third_party/v8_inspector/platform/v8_inspector: vendored from https://chromium.googlesource.com/chromium/src/third_party/WebKit/Source/platform/v8_inspector
+* third_party/v8_inspector/platform/inspector_protocol: vendored from https://chromium.googlesource.com/chromium/src/third_party/WebKit/Source/platform/inspector_protocol
+* third_party/jinja2: vendored from https://github.com/mitsuhiko/jinja2
+* third_party/markupsafe: vendored from https://github.com/mitsuhiko/markupsafe