vim: backbone.vim: Give the 'this'-from-function getter a better name.
vim: backbone.vim: Remove the 's:this' variable.
vim: backbone.vim: Add a function that emulates the behavior of the
Backbone extend() helper function.
vim: backbone.vim: Fix issues in _CreateModel() and _ExtendType().

+ In _CreateModel(), the function was converted to a dictionary function
  so that the instance is created from the self dictionary, which
  contains the extended Model class.
+ In _ExtendType(), deep-clone the parent class' properties or else we
  end up extending the parent.
vim: backbone.vim: Add the cid and attribute properties in the Model
constructor.
vim: backbone.vim: Add the remaining Model members.
vim: backbone.vim: Clean up.
vim: backbone.vim: Add the initial completion support for
Backbone.Collection.
.vimrc: Set neocomplcache to overwrite the completefunc setting.