scons: Require SCons version 0.98.1

This allows me to clean things up so we are up to date with respect to
deprecated features.  There are many features scheduled for permanent failure
in scons 2.0 and 0.98.1 provides the most compatability for that.  It
also paves the way for some nice new features that I will add soon

ext/libelf/SConscript

@@ -87,7 +87,7 @@ ElfFile('libelf_convert.c')
 ElfFile('libelf_fsize.c')
 ElfFile('libelf_msize.c')
 
-m4env = env.Copy()
+m4env = env.Clone()
 if env['GCC']:
     major,minor,dot = [ int(x) for x in env['CXXVERSION'].split('.')]
     if major >= 4: