Bug unparsing JS function
WIP: Transactional: Wrap every JS expression with parenthesis

As CODE and codegen have to live together for a while, we can't deal
with the precedence/associativity easily. We use parenthesis in every
expression around ls-compile not to break the REPL.
Toplevel empty statement are empty strings
Migrate js!bool and js!selfcall
Merge branch 'codegen' into codegen-migration
Migrate IF
Migrate some more primitives
Migrate IN
NTH-VALUE macro
Do not upcase variable names JS identifiers
Fix empty toplevel progn
Fix MAPC
Merge branch 'master' into codegen-migration
Migrate LAMBDA-NAME/DOCSTRING-WRAPPER
Migrate %WHILE
Migrate DUMP-ARRAY
Migrate DUMP-SYMBOL
Migrate DUMP-CONS
Migrate SETQ
Remove unnecesary CODE