Backport header improvements from 5.0

Motivation:
The header class hierarchy and algorithm was improved on the master branch for versions 5.x. These improvments should be backported to the 4.1 baseline.

Modifications:
- cherry-pick the following commits from the master branch: 2374e17, 36b4157, 222d258

Result:
Header improvements in master branch are available in 4.1 branch.