Version-safe customer login form

The trick is an extra module which loads before captcha if it exists.
New module creates 'form.additional.info' block in case captcha doesn't.
If Mage_Captcha is active it recreates the same block.
Later modules may use either without realising who created it.
Rememberme module now relies on 'form.additional.info' text list.

New module also comes with ideal template including persistent features.

modman and package descriptor files are updated to match.
Specific checkbox template for RWD theme
Rename ambiguous 'form' dir to 'customer'
Apply loginformfallback to onepage checkout

Onepage login form now creates 'form.additional.info' text list.
Behaves the same as customer account login form.
Template 'rememberme/checkbox.phtml' is shared between both forms.
Template 'rememberme/checkout/login.phtml' has been removed.
Update version to 0.5.0

Package descriptor updated to match and ready to publish.