Optimize for speed and memory.
JIRA issue: CORE-13950
CDirectoryList class exists just for remembering which file item is a directory or
not, in order to notify the filesystem item changes. This information can
become a tree data structure.
- Add CFSPathIterator and CFSNode helper classes.
- CFSNode is a class for tree nodes.
- Re-implement CDirectoryList class by using tree nodes.
- Delete CDirectoryItem class.
Improve human readability of filesystem change notification.
- Rename the identifiers for human readabilities.
- Split the code into CFilePathList and CDirectoryWatcher classes.
- Encapsulation of code.
CORE-13950
