feat(library/data/int/basic): create alias for int.int
feat(library/hott): add 'path' namespace
feat(library/coercion): rename class to 'coercions'
feat(frontends/lean/pp): add 'pp.beta' option, closes #154
feat(shell): start 'lean --server' with 'pp.beta = true'
feat(shell): start 'lean --server' with 'pp.beta = true'