Added support for scheme-relateive urls

Response::redirect will now support the following forms of URLS:

Scheme relative: "//domain.com/page" or "//ipaddress/page"
Absolute: "protocol://page"
Relative to this domain: "/page"
Relative to this page: "page"
Templates can now have multiple groups.

Templates can now have multiple groups. Paths for specific template
items are no longer supported.  Instead, append a path for the template
group and add any desired templates there.  Templates paths added last
will be searched first:

  Config::merge(array('template.groupname' => array('/path1')));
  Config::merge(array('template.groupname' => array('/path2')));

Paths:

  array('/path1', '/path2');
Added missing files
Template file can be directly specified.

The template can now specify a file directly with Template::getFile.
Also, Template::get and Template::getFile now allow an override
parameter which, if true, will cause the parameters passed to entirely
replace any existing parameters instead of being merge with existing
parameters.  After the template is processed, original parameters will
be restored.