Add srecode manual to build process

Add srecode manual to build process

* doc/misc/srecode.texi: Small edits.  Set copyright to FSF, add explicit
GFDL 1.3+ license, fix up index.

* doc/misc/Makefile.in (INFO_TARGETS, DVI_TARGETS, PDF_TARGETS): Add srecode.
(srecode, $(buildinfodir)/srecode$(INFO_EXT), srecode.dvi)
(srecode.pdf): New targets.

* doc/misc/makefile.w32-in (INFO_TARGETS, DVI_TARGETS, clean): Add srecode.
($(infodir)/srecode$(INFO_EXT), srecode.dvi): New targets.

* info/dir: Add srecode.