This takes an array of folders and attaches them together according to the hierarchy described by their full_names and separator
.
If namespace_ is non-null, then it will be ignored as a full_name prefix, for purposes of
comparison. If necessary, folder_info_build will create additional
FolderInfo with null urls to fill in gaps in the tree.
The value of short_names is used in constructing the names of these intermediate folders.
| folders |
an array of FolderInfo |
| namespace_ |
an ignorable prefix on the folder names |
| separator |
the hieararchy separator character |
| short_names |
true if the (short) name of a folder is the part after the last |
|
the top level of the tree of linked folder info. |