Doc: Added note to CG about disable-optimizing (issue 5081048)

[tdanielsmusic]

LGTM, with one comment


http://codereview.appspot.com/5081048/diff/1/Documentation/contributor/regressions.itexi
File Documentation/contributor/regressions.itexi (right):

http://codereview.appspot.com/5081048/diff/1/Documentation/contributor/regressions.itexi#newcode143
Documentation/contributor/regressions.itexi:143: be run with the
@code{--disable-optimising} option.  Then you will need
I think I'd mention just running ./autogen, just in
case the reader is doing the build for the first time.
But if you leave the configure option in it should be
./configure.

http://codereview.appspot.com/5081048/