Move PD_BUILD_VERSION from s_stuff.h.in to s_version.h.in

#397

Relevent makefiles and source files that use the PD_BUILD_VERSION variable are also updated. Not sure if I got all the comments updated. Tested with a clean compilation on Windows 10 and the build succeeded smoothly.

I also noticed that, in the repo, there are a few files (that seem to be) generated during build phase and should be ignored, including:

• externals/OSCx/libOSC/Makefile
• externals/OSCx/send+dump/Makefile
• externals/OSCx/src/Makefile
• externals/build/include/g_all_guis.h

Is my understanding correct? Should I remove them and add them to .gitignore?

debuild/Makefile

@@ -103,9 +103,9 @@ $(debsrc):
 	git -C .. archive --format=tar.gz --prefix=$(debdist)/ HEAD | tar xfz -
 # Grab the submodules.
 	for x in $(submodules); do (cd $(debdist) && rm -rf $$x && git -C ../../$$x archive --format=tar.gz --prefix=$$x/ HEAD | tar xfz -); done
-# Pre-generate and put s_stuff.h into the tarball (see above; the build
+# Pre-generate and put s_version.h into the tarball (see above; the build
 # version is generated using git which can't be done outside the git repo).
-	sed 's|^\(#define PD_BUILD_VERSION "\).*"|\1$(PD_BUILD_VERSION)"|' ../pd/src/s_stuff.h.in > $(debdist)/pd/src/s_stuff.h
+	sed 's|^\(#define PD_BUILD_VERSION "\).*"|\1$(PD_BUILD_VERSION)"|' ../pd/src/s_version.h.in > $(debdist)/pd/src/s_version.h
 # Create the source tarball.
 	tar cfz $(debsrc) $(debdist)
 	rm -rf $(debdist)