fix(library/data/category): mark definitions as abbreviations
fix(frontends/lean/builtin_cmds): allow coercion command inside section, fixes #186
fix(library/coercion): remove spurious '\n'
feat(library/coercion): better support for coercions to function-class. closes #185
refactor(emacs/debug): rename lean-server-debug to lean-debug
refactor(emacs/lean-server): rename flush-changed-lines to server-flush-changed-lines
feat(emacs/lean-changes): handle before/after-revert