color: don't split colors across lines (which confuses less -R)
Currently, less -R doesn't support colors spanning multiple lines; only
the first line will be colorized.
Instead of allowing colors to span multiple lines, the color extension
now applies colors to each line it receives, even when ui.write() is
given multiple lines in one call.
% should fail
abort: path contains illegal component: .hg/00changelog.i
adding a/a
% should fail
abort: path 'b/b' traverses symbolic link 'b'
% should succeed
% should still fail - maybe
abort: path 'b/b' traverses symbolic link 'b'
% unbundle tampered bundle
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 6 files (+4 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
% attack .hg/test
.hg/test
abort: path contains illegal component: .hg/test
% attack foo/.hg/test
foo/.hg/test
abort: path 'foo/.hg/test' is inside repo 'foo'
% attack back/test where back symlinks to ..
back
back/test
abort: path 'back/test' traverses symbolic link 'back'
% attack ../test
../test
abort: path contains illegal component: ../test
% attack /tmp/test
/tmp/test
abort: No such file or directory: [HGTMP]/test-audit-path/target//tmp/test