This is a beg-forgiveness-review-request. Would someone do me a favor and sanity-check the staff_client/server/skin/custom.js.example file in master? Previously the default dump statement provided by Javascript was overwritten in the staff client with one that can take an optional second parameter for a log level, and compare against a global _dump_level variable to determine whether to actually produce output or not, and to also look for a global _dump_prefix variable and prefix the output with its value. The default dump_level makes the client much less noisy in the console than it used to be. A value of 4 would make it noisy again.
The custom.js.example file (which you would need to rename or copy to custom.js in server/skin) uses preferences to alternate the _dump_prefix whenever custom.js is loaded (essentially, for each page/interface), and to also set the _dump_level variable based on a user-supplied oils.dump_level preference (you would need to add this through Admin->For Developers->about:config, click through any warning, and then right-click on any listed preference and choose New->Integer)
Works as designed - thanks Jason!