Added packagist bling

Poser badges for restler from https://poser.pugx.org/
Enabling restler/framework as a sleek repository with just the class files
Fixing composer.json to support package versioning with git tags
Bump version number to 3.0.0rc5
Adding Scope, new class that acts as DI container and replaces the class initiation functions in Util class
Improved Scope with class comments
Improves Scope, to include Restler as part of the scope using newly added set method
Improves Restler, to make use of Scope
Removes unneeded methods from Util as they are replaced by Scope
Improves Restler, to use Scope for storing apiClassInstance instead of hard coded reference
Improves Restler, to remove reference to apiClassInstance in validate stage
Fixes Restler for the postCall method bug
Improves Restler, to set the value of the parameter to be validated to null just before validation, and to mark them as the current field with autofocus. This will help Forms to reset that field and bring focus to them
Improves Restler to make sure we go through `route` stage when exception happens at the `get` stage
Improves Restler, to convert the Exception to RestException when thrown at `get` stage
Improves Restler by setting the default request data when exception is thrown at `get` stage
Fixes HtmlFormat to check for view path and set basePath and baseUrl at encoding stage instead of the constructor to balance for the Scope way
Fixes RestException to use Scope to get the restler instance
Fixes HumanReadableCache to use Scope to get the restler instance
Fixes Compose to use Scope to get the restler instance