* Remove parens around UpdateExpression when parent is CallExpression.

* Add new test case.

```js
// test.js
var prettier = require('./');
prettier.format('a=1');
```

```js
node test.js
// doesn't crash
```

) (#798)

* Add new handleFunctionDeclarationComments function.

* Add dangling comments printing for function params.

* Add new test case.

* Update tests.

* Refactor handleFunctionDeclarationComments to only addDanglingComment when no params.

* Remove unecessary helper function, only attach dangling comments when no params.

* Reset flow tests, no more regression.

This fixes the bug with comments swapped between `/*` and `//`

Fixes #755

* Implement new heuristic for arguments in printArgumentsList function.

* Remove unwanted modification.

* Add new helper function.

* Update tests according.

* Add new tests for #682, #677, #253.

* Move heuristic in groupLastArg condition.

* Update tests.

The code that supported `do` was likely from some recast time and didn't work anymore.

We need to add parenthesis around function expressions if they are named otherwise the name leak, but if the function is not named then it's just superfluous.

The conditional change is due to a bad use of switch case where it would fall through the next one. We don't want parenthesis there.

I also added support for parser dropdown and stop minifying the bundle so that the flow parser actually works.

Fixes #816

By adding a group, we can avoid adding a newline if the expression fits in a single line.

Fixes #800

The `hasLeadingOwnLineComment` helper is going to be useful for other places where we just used `n.comments` as a proxy for it.

Fixes #660

Printing a merged group indented was actually not the right fix. The right fix was to print them in a single line. It used to have this behavior when I was mutating the first group but now that I don't anymore I need to reproduce this condition.

Fixes #823

Instead of trying to figure out a complicated way to preserve their correct position, it's easier to just migrate those comments before the class.

Fixes #693
Fixes #694

I'm not really sure what a general rule is for those, but starting with LogicalExpressions should be good. Outside of identifiers, function calls and logical expressions, there aren't a lot of things you'd put there in real code anyway.

Fixes #822