Minor quoting etc. fixes to lispref manual

Minor quoting etc. fixes to lispref manual

* doc/lispref/tips.texi (Documentation Tips):
Distinguish more clearly among grave accent, apostrophe,
and single quote.
* doc/lispref/README, doc/lispref/buffers.texi:
* doc/lispref/commands.texi, doc/lispref/control.texi:
* doc/lispref/customize.texi, doc/lispref/display.texi:
* doc/lispref/elisp.texi, doc/lispref/files.texi:
* doc/lispref/frames.texi, doc/lispref/hash.texi:
* doc/lispref/help.texi, doc/lispref/internals.texi:
* doc/lispref/loading.texi, doc/lispref/makefile.w32-in:
* doc/lispref/markers.texi, doc/lispref/modes.texi:
* doc/lispref/nonascii.texi, doc/lispref/objects.texi:
* doc/lispref/os.texi, doc/lispref/positions.texi:
* doc/lispref/strings.texi, doc/lispref/syntax.texi:
* doc/lispref/text.texi, doc/lispref/tips.texi:
* doc/lispref/two-volume-cross-refs.txt, doc/lispref/windows.texi:
Use American-style double quoting in ordinary text,
and quote 'like this' when single-quoting in ASCII text.
Also, fix some minor spacing issues.