Making Images Responsive via CCS or Bootstrap?

OC3.0.2.0

is it possiable to add >> class="img-responsive" << for all images on a default theme, via ccs or bootstrap, i know i can add it manually to images but can it added to already present code? im after it to only affect the image uploaded to information pages etc, if it can which file should i be looking at updating it in?

<img src="http://www.xxxxxxxx.co.uk/image/catalog ... -theme.jpg" style="width: 752px;" class="img-responsive">

in "bootstrap.min.ccs" is a matter of the following
From This
img{vertical-align:middle;}

to this?
img{vertical-align:middle;max-width: 100%;height: auto;}

Thank you for your time
Ste

Sorry posted in bug area, should have been in general support

img{vertical-align:middle;max-width:100%!important;height: auto;}
should do better !
Ernie

Thank you Ernie, super star once again.