Style cleanup

This is a cleanup to meet Kohana's [Coding Style guidelines](http://kohanaframework.org/3.2/guide/kohana/conventions), as checked with https://github.com/kohana/coding-standards and [PHP_CodeSniffer](http://pear.php.net/package/PHP_CodeSniffer]).

This is part 1 of the cleanup, which fixes the guidelines related to whitespace, parens, braces, and AND/OR.  This pull request resolves around 280 PHP CodeSniffer errors.

I ran PHP CodeSniffer using:
```bash
phpcs --report=checkstyle --report-file=~/kohenkatz-mongodb-php-odm.log.xml --standard=Kohana ~/projects/github/kohenkatz/mongodb-php-odm/
```