changes the way collection's $reset and $feed work

$reset will no longer clear the collection contents, if called then
the next call to $feed will clear the contents. This means that $fetch
will no longer clear the contents unless $reset is called first. With
that in mind a new method named $refresh is added to $reset and $fetch.
debounced: fixes promises not being resolved if debounced
adds the paged plugin
bumps version 0.6.0