node sources are gpl-v3 as well

Checked with all authors.
node: code cleanup using splint

 * use bool to avoid conversion warnings
 * missing /*@noreturn@*/ and /*@only@*/ declarations
fix swap plugin to not use bools for integers
document what version of munin the plugins follow
inet_aton returns zero on failure
Merge commit 'node: use lowercase version of automatic hostname'
remove dysfunctional install-exec-hook

The hook is a noop, because the $(LINKS) variable is undefined. It was
removed earlier and thus rendered the install-exec-hook a noop. It is
not clear whether symlinks in $(pkglibexecdir) are actually useful, so
for now this piece of dead code is discarded.
Makefile.am: add $(EXEEXT) to binary filenames

These are required for operation in win32 environments. Without the
extension, the operating system refuses to run the code.

Signed-off-by: Helmut Grohne <helmut@subdivi.de>
Signed-off-by: Steve Schnepp <steve.schnepp@pwkf.org>
p/memory: support 32bit systems with more than 2G memory

Signed-off-by: Helmut Grohne <helmut@subdivi.de>
Signed-off-by: Steve Schnepp <steve.schnepp@pwkf.org>
plugins: adding an external_ wildcard plugin
plugins: reorder source files to ease future diffs

We put main.c at the end of the list to each plugin can be added
alphabetically, without always changing the last backlash hanling