topic: use preformatted block for config snippets documentation We add :: markers, empty line and properly indent blocks where needed.

tests: add a test for "hg help -e topic" Currently, some configuration snippets do not render well; we'll fix this in forthcoming changesets.

branching: merge with stable

content-div: add test showing `--stop` works during interrupted resolution This patch adds a test showing that the --stop flag of `hg evolve` works well during interrupted content-divergence resolution. The --stop flag now works with all the three different type of instability resolution very well and we should advertise it more.

evolve: create new commit while resolving content-divergence Before this patch, we used to amend one of the content-divergent changes with the changes from the merge. Creating a new commit will certain advantages like letting user enter a commit message, showing user the new merge diff before commiting the content-divergent resolution and give us more control in the implementation part. The reason amend was used initially was just because it was easy. There are some tests update due to change.

content-divergence: store the resolved revs in evolvestate['replacements'] The support for continuing a conflicted content-divergence resolution was added some time ago. That support lacked storing of the resolved rev in the evolvestate['replacements'] which marks the node as resolved and does not try to resolve that node again. Since we didn't store, the resolution, processes the same node again. This patch makes sure we store the information in evolvestate that a certain content-divergent node is resolved to prevent pre-processing it again.