DevTools: Concatenate dynamic modules by the build_applications.py script

DevTools have a distinct target for the concatenation of each dynamic module.
This scales poorly and is error-prone. Having the build_applications.py
script concatenate them completes the migration of the JavaScript part
of the build to the script-based solution for non-debug_devtools builds.

R=dgozman@chromium.org, pfeldman, vsevik

Review URL: https://codereview.chromium.org/612383003

git-svn-id: svn://svn.chromium.org/blink/trunk@183044 bbb929c8-8fbe-4397-9dbb-9b2b20218538