that's not a bug report, please use the project "Development" or "Feature Request"

Well, it is an "issue" because it makes debugging hard due to the noise in browser console.

I 100% agree there is way too much noise on the console.
So you could open a bug called: "Too much noise in the console"

Updated this issue.

@markusfluer: please, don't brutally turn off all console logs when debug mode is off. Remember that many user who will report problems can't access file system and Debug state.
So we still want errors and warning to appears on the console. But only the relevant things.

How to discern a really important thing from a not so important?
IMHO we should add a basic script, that does give an interface to the logging functionalities.
With failsafe for older or incompatible browsers, but this should be used by everyone then.
I've build a prototype of it into the adminpanel, the logging mechanics used there could be bound to the global scope, creating a global $log object with methods log, warn, error and debug.
We could also add grouping to it.

But I would need all of you on board, because this is of no use if it isn't used.
Also it would take time to implement it everywhere and discern the important errors, from unimportant debug statements.
This could be done gradually, though.

Not important: everything works as wanted (Default template freshly installed), and the console is still full of noise
Important: something break JS, so nothing is loaded anymore, we need an error or something.

Partly fixed with 12956

To finall yremove all traces we need to get rid of jqueryui since it is in a severly outdated state.

Added a global setting to define the level of js logging

Fix committed to develop branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&id=25521

Version 3.0.3 released.