contrib/highlight-log: use single sed pipe  [ci skip]
contrib/highlight-log: use single sed pipe  [ci skip]

Otherwise it would get buffered (more).

Use extended regexp for all expressions.

The later `-E` appears to enable it for all expressions.

nerdrew/neomake,neomake/neomake,codeinabox/neomake,neomake/neomake,nerdrew/neomake