Previously we saw a bug that when we have nested if statements
and an alternate then the generated code may confuse which
if statement the alternate belongs to.
e.g.
```
if (foo) if (bar) bar(); else baz();
```
But this was handled by looking at the consequent
and if it's an if we add a block. However we didn't
handle situations where it's not an if but the last
recursive statement is an if:
```
if (foo) while (bar) if (baz) baz(); else shoosh()
```
This handles it by recurring until we get the last
statement.
As a follow up from #3145 we agreed to add a new format that is a
superset of the compact format option. Do things that are considered
dangerous. e.g. not printing semicolons, or print literal values
as opposed to raw values.
I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.
