+ uniqlist now uses twiddle, tolerance removed from uniqlist, duplicated and unique
+ added twiddle() at R level for test/illustration purposes
+ Removed duplist

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1164 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
duplist.R & .c renamed to uniqlist.R & .c

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1165 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
+ bmerge uses twiddle.  
+ tolerance no longer used anywhere, just in one place inside twiddle

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1166 edb9625f-4e0d-4859-8d74-9fd3b1da38cb