Merge branch 'sig2'

common/server/impl.go

common/sig/entry.go

common/sig/entry_test.go

common/sig/normalize.go

common/sig/parser/README.md

common/sig/parser/array.go

common/sig/parser/basic.go

common/sig/parser/builder.go

common/sig/parser/context.go

common/sig/parser/func.go

common/sig/parser/parsers/v0/parser.go

common/sig/parser/parsers/v0/parser_test.go

common/sig/parser/signature.go

common/sig/parser/sub.go

common/sig/parser/tuple.go

common/sig/parser/type.go

common/sig/parsing.go

common/sig/types.go

common/sig/types/valid.go

common/store/stores/memory/store.go