Added a method to fluently set belongs-to relation

This method spun off from a discussion in IRC. What this enables is this:

$user->comments()->insert($comment_data)->article()->bind($article->id)
Removed a Useless if conditional from bind method
Add unit tests for date_format validator rule.
Implement date_format validation rule.
Add documentation for date_format validation rule.
Reformatted return

Changed the return of the method in line with suggestions from @JoostK.
Fix CLI mode detection for some shared hosts.
Added PDO error code
Setting the exception code in the constructor
Use Request helper to determine whether we're in CLI mode.
add use Closure;
Undefined namespace Grammars
Update laravel/database/connection.php
Merge pull request #2 from laravel/develop

Develop
Add task bundle:uninstall, bundle:unpublish, migrate:rollback bundle, migrate:reset bundle.
Add another test with quotes around the validation rule's parameter.
Fix validation tests one more time.
segment pattern to match a single segment, also matches UTF-8 segments.
added 'u' flag for preg_match to match UTF-8 URIs.
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