Merged in david_s5/nuttx-5/david_s5/there-is-a-return-path-with-node-not-set-1486503652666 (pull request #204)

There is a return path with node not set

Approved-by: Gregory Nutt

inode/fs_inoderemove.c: In function 'inode_unlink':
inode/fs_inoderemove.c:74:17: warning: 'node' may be used uninitialized in this function [-Wmaybe-uninitialized]
   FAR struct inode *node;

up_timer_initialize() is named incorrectly.  The prefix should be the architecture name, not up_ since it is private to the architecture.  up_timerisr() is similarly misnamed and should also be private since it is used only with the xyz_timerisr.c files.  Also updat TODO list.

Soft link: Change how a value is returned so that _inode_linktarget will function in all of its use contexts.

Soft links:  Eliminate in-stack allocation of path working buffer needed for traversal fo paths with soft links.

Add macros support that will eventually allow dynamic allocation of strings need to support soft links.

tools/noteinfo.c: A hack tool that I use to analyze some sched_note output.  Needs a home and may be useful to others.

inode_find:  Now takes struct inode_desc_s type as input.  This was necessary before that structure includes some data storage.  It was used within inode_find(), but that means that the life of the data was the life of inode_find().  That data must persist longer.  It is now provided by the caller so that the life of the data persists for the entire life of the caller.

FS: Remove inode_search_nofollow().  That logic is no handled with a new field in the input argument structure.

Soft links: Fix logic and remove kludge of last commit.  Rename inode_dereference() as inode_linktarget() and make global.

FS: Separate inode_search() and inode_free() from fs_inode.c and put in separate files.  Flesh out symbolic link logic in stat() and readdir().  There are still some issues with stat().