templates: adjust white space amount in the output of {whyunstable} There used to be 2 spaces between divergent nodes (when not using custom template for divergentnodes) because divergentnodes is a hybrid list, which means it gets ' '.join()ed, but formatnode() already had a space. Now it doesn't, which requires extra effort in writing custom templates for whyunstable, but at least it looks correctly by default. Test output needs to be sorted for stability.

tests: split long templates that use {whyunstable} and put them in hgrc

tests: make custom templates that use {whyunstable} terser These templates demonstrate that {whyunstable} is fully template-friendly, but they don't need to produce such long lines of output.