switch Favorites portlet to use FAVORITE_COLLECTION type rather than REGULAR type

Instead of considering "regular" layout tabs to be favorited collections, instead consider a purpose-specific FAVORITE_COLLECTION type
read u_focusedFragmentId from URL and feed it to structure transform
initial stab at supporting focusedFragmentId
Log layout XML and fragment activation to a layout.log

Will probably want to revert this before merge, but very useful for troubleshooting favorites use of layout fragments and rendering of favorite collections.
declare focusedFragmentId stylesheet parameter
portal logo links to "home" of portal
add trace logging of stylesheet parameter setting
switch UserLayoutParameterProcessor to use slf4j
add logging of focusedFragmentId processing
include focusedFragmentId in <debug/>
include regions in focused-on-one-fragment rendering
Link to view a collection addresses by focusedFragmentId.
Represent the focused-upon fragment as a single navigational tab.

This makes the render at least show the name of the focused-upon fragment, though this UI is not ideal and not yet what's in the mockups.
suppress add tab control when viewing a single fragment in focused mode

this is necessary because currently single fragment in focused on is (clumsily) represented as essentially a virtual layout with a single tab.
normalize indent of focusedFragmentId parameter declaration
use folder-name in portal URL instead of focusedFragmentId to identify focused-upon non-regular fragment

Rolls back bad-idea introduction of `focusedFragmentId` parameter.
Instead computes focused fragment id from focusedTabID
and signals from structure to theme with a new `@allowAddTab` attribute on <navigation>
logging enhancements

adds trace logging
converts some code comments to log statements
Document that getFolderNamesForLayoutNode implementation returns List of length zero or one.

Add implementation note documenting doesn't-seem-quite-to-API-spec behavior of method implementation.
revert to addressing favorite collections by folder name
switch to non-String-concat-style log message composition

Avoids having to to-string the portalRequestInfo when not logging at DEBUG level while also not having to gate the log statement.