Allow falsy ID for plans

I encountered this issue, and saw that this was already reported in #55.
The fix I've included will solve the issue, but might impact other things, so this should be tested carefully.
Add test for plan, allow falsy id in request, add composer.phar to .gitignore
Revert weird changes
Update changed files to kind of follow zend style guide.
generalized Card class to support customers or recipients
added tests for customer cards
added recipient tests
Fix typo in SSL check warning
updated tests to dynamically generate expiration year
Merge pull request #83 from danielchatfield/fix-typo

Fix typo in SSL check warning
diagnosing php <= 5.3 errors
Merge branch 'master' of github.com:KorvinSzanto/stripe-php into KorvinSzanto-master

Conflicts:
	lib/Stripe/ApiResource.php
	lib/Stripe/Object.php
	test/Stripe/PlanTest.php
Merge branch 'KorvinSzanto-master'
Merge conflicts
refactored Card instanceUrl()
Fix formatting in test
more refactoring for Card model
instanceUrl returns null for missing customer/recipient field
Merge pull request #82 from stripe/stephen-recipient-cards

Added support for recipient cards, tests for customer and recipient cards
Bump version.