Started to rescind the name "skin", replacing it with "tool".  Did this in all
the places that normal users will see:

  - command line: --tool=foo (although --skin=foo still works)
  - docs: removed all traces (included renaming coregrind_skins.html to
    coregrind_tools.html)
  - in the usage messages
  - in error messages

Also did in in some places that I judged were unlikely to cause clashes with
existing workspaces:

  - in the header comments of many files (eg. "This file is part of Memcheck, a
    Valgrind tool for...")
  - in the regtests script
  - in the .supp files
  - in AUTHORS
  - in README_MISSING_SYSCALL_OR_IOCTL

Also update the AUTHORS file to mention Jeremy.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2027 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/vg_errcontext.c b/coregrind/vg_errcontext.c
index 7f4f729..89baa24 100644
--- a/coregrind/vg_errcontext.c
+++ b/coregrind/vg_errcontext.c
@@ -212,7 +212,7 @@
       Char* name = SK_(get_error_name)(err);
       if (NULL == name) {
          VG_(message)(Vg_UserMsg, 
-                      "(skin does not allow error to be suppressed)");
+                      "(tool does not allow error to be suppressed)");
          return;
       }
       VG_(printf)("   %s:%s\n", VG_(details).name, name);