evolve: add logic to resolve content-divergence with a public cset Public content-divergence is the divergence where a cset is content-divergent with a public cset. To solve public divergence: 1) perform content-divergent resolution 2) resultant node is phase divergent 3) perform phase divergence resolution It is the intial logic to solve public divergence. Next patches will be the covering the cases of: 1) relocation: when we need to relocate to node 2) continue: to add this resolution in case of --continue 3) the case when content-divergence resolution gives a result similar to public cset. Added test-evolve-public-content-divergent.t reflect the added behaviour.

evolve: introduce function to create a obsmarker relation even for public cset To create obsmarkers we use obsolete.createmarkers() function, but because of security reasons this function refuses to create obsmarkers for public cset. And we need to create obsmarkers for a public cset while solving public content divergence. So introducing this function which create a obsmarker relation even for immutable cset. Currently this function create obsmarker for a single relation, in contrast of obsolete.createmarkers() which create markers for multiple relations. Upcoming pathces will be using this function.

topic: make ranges work in revset relations like 'foo#stack[1:2]'