Api.py Pep8 style compliance

##### [Pep8](http://www.python.org/dev/peps/pep-0008/) style changes:
* Don't use spaces around the = sign when used to indicate a keyword argument or a default parameter value. 
 * `form._send_data(iden = iden)`
 * `form._send_data(iden=iden)`
* EOL white space 
 * `form._send_data(iden=iden) \n`
 * `form._send_data(iden=iden)\n`
* Avoid whitespaces immediately before the open parenthesis that starts the argument list of a function call.
 * `log_text ("foo")`
 * `log_text("foo")`
* Continuation lines should align wrapped elements either vertically using Python's implicit line joining inside parentheses, brackets and braces, or using a hanging indent.
 * [L197-198](https://github.com/reddit/reddit/blob/master/r2/r2/controllers/api.py#L197-198)
* Compound statements (multiple statements on the same line) are generally discouraged.

```
if not thing: return
```
```
if not thing:
    return
```

##### Not changed:
* Unused variables, e.g. [L411 `r = l._save(c.user)`](https://github.com/reddit/reddit/blob/master/r2/r2/controllers/api.py#L411)
* Unused imports, e.g. [L34 `from pylons import response`](https://github.com/reddit/reddit/blob/master/r2/r2/controllers/api.py#L34)
* Limit all lines to a maximum of 79 characters, e.g. [L1717](https://github.com/reddit/reddit/blob/master/r2/r2/controllers/api.py#L1717)