bug#22715: 25.0.91; Point randomly jumps during key entry

[Steve Revilak]

I patched the 29.0.91 pretest sources with diffs from these two
commits:

---------------------------------
commit aa5a7948431437fc09931ac21eb05f365e1f8876
Author: David Engster <deng@...>
Date:   Sun Feb 21 17:16:45 2016 +0100

    Remove `semanticdb-save-all-db-idle' from `auto-save-hook'

    * lisp/cedet/semantic/db-mode.el (semanticdb-hooks): Do not put
      `semanticdb-save-all-db-idle' into `auto-save-hook'. The latter is
      not an idle hook, so it's not appropriate to call it there. It will
      already be called in the `semantic-idle-work-core-handler', which
      runs when Emacs is actually idle.

commit 2d8b2fd034ccc61f949b408373342b5f9f8ba592
Author: David Engster <deng@...>
Date:   Sun Feb 21 17:11:01 2016 +0100

    Restore point when writing semantic table to disk

    * lisp/cedet/semantic/db-file.el (object-write): Wrap call to
      `semantic-fetch-tags' in `save-excursion', since it might move point
      in current buffer. (Bug #22287)
---------------------------------

I'll work with these changes for a while, and report back with my
findings.