Drop references to makefile targets which no longer exist.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4867 7894878c-1315-0410-8ee3-d5d059ff63e0

doc/developers/makefiles

@@ -18,11 +18,6 @@ There are several interesting targets defined through this Makefile:
     of 'make clean' (without any other targets) will ignore any .d files;
     this is useful when they are out of date (and prevent the calling of
     any other target).
-  * version
-    Regenerate version.h, using the current date for the date-stamp, and
-    a user-supplied version number.
-  * package
-    Create a .tar.gz file containing everything except the SVN directories.
 
 The best way to understand the Module.mk subfiles is to examine one of them,
 for example lib/Module.mk. They are not too difficult to understand.
@@ -47,13 +42,13 @@ Several files are generated by Makefiles:
     Dependency files for shared libraries. Automatically generated.
   * .ro
     Object files for executables. They will be linked together to create
-    the executable. This extension is used to distinguish them from 
-    modules (which end on .o). Also, using a different extensions makes
-    the Makefile fragments much simpler.
+    the executable.
   * .ao
     Object files for static libraries
   * .lo
     Object files for shared libraries
+The reason for using different extensions is to make the Makefile much
+simpler.
 
 There are lots of comments within the main Makefile. Please read them if
 you want to know more.