Also add "make syntax-check" rules to ensure no new uses sneak in.

There are many uses of write like this:

    if (write (fd, xml, towrite) != towrite)
        return -1;

The problem is that the syscall can succeed, yet write less than
the requested number of bytes, so the caller should retry
rather than simply failing.

This patch changes most of them to use util.c's safewrite wrapper,
which encapsulates the process.  Also, there were a few cases in
which the retry loop was open-coded, and I replaced those, too.

* Makefile.maint (sc_avoid_write): New rule, to avoid recurrence.
* .x-sc_avoid_write: New file.  Record two legitimate exemptions.
* qemud/qemud.c (sig_handler, qemudClientWriteBuf): Use safewrite, not write.
* src/conf.c (__virConfWriteFile): Likewise.
* src/qemu_conf.c (qemudSaveConfig, qemudSaveNetworkConfig): Likewise.
* src/qemu_driver.c (qemudWaitForMonitor, qemudStartVMDaemon)
(qemudVMData, PROC_IP_FORWARD): Likewise.
* proxy/libvirt_proxy.c: Include "util.h".
(proxyWriteClientSocket): Use safewrite.
* src/test.c (testDomainSave, testDomainCoreDump): Likewise.
* src/proxy_internal.c (virProxyWriteClientSocket): Likewise.
* src/virsh.c: Include "util-lib.h".
(vshOutputLogFile): Use safewrite.
* src/console.c: Include "util-lib.h".
(vshRunConsole): Use safewrite.

We currently use safewrite from inside libvirt and don't want to publish
any such function name.  However, we do want to use it in applications
like virsh, libvirtd and libvirt_proxy that link with libvirt.  To that
end, this change moves that function definition (along with the nearly
identical saferead) into a new file, util-lib.c.  To avoid maintaining
separate copies of even such small functions, we simply include that new
file from util.c.  Then, the separate applications that need to use
safewrite simply compile and link with util-lib.c.

Of course, this does mean that each of those applications will
containing two copies of these functions.  However, the functions
are so small that it's not worth worrying about that.

* src/util.c (saferead, safewrite): Move function definitions to
util-lib.c and include that .c file.
* src/util-lib.c (saferead, safewrite): New file.  Functions from src/util.c
with slight change (s/int r =/ssize_t r =/) to reflect read/write return type.
* src/util-lib.h: Declare the two moved functions.
* src/util.h: Remove declarations.  Include src/util-lib.h.
* proxy/Makefile.am (libvirt_proxy_SOURCES): Add src/util-lib.c.
* qemud/Makefile.am (libvirtd_SOURCES): Likewise.
* src/Makefile.am (virsh_SOURCES): Add util-lib.c.  Remove some SP-before-TAB.

* src/iptables.c (iptRulesSave) [!ENABLE_IPTABLES_LOKKIT]:
Mark parameter as used.

* tests/statstest.c (testQuietError) [!WITH_XEN]: Don't define.

* src/openvz_conf.c (openvzSetUUID): Rewrite to avoid unchecked
lseek, write, and close as well as a potential file descriptor leak.

* src/openvz_conf.c (openvzLocateConfDir, openvzGetVPSUUID):
(openvzSetUUID): Don't dereference NULL upon failure.

        * src/openvz_conf.c: Double-free fix (Anton Protopopov).

* docs/examples/index.py: Don't emit trailing blanks.
* docs/examples/Makefile.am: Regenerate.

* bootstrap (gnulib_tool): Add useless-if-before-free to
the list of modules.
* build-aux/useless-if-before-free: Update from gnulib.
* gnulib/lib/vasnprintf.c: Work around a bug in HPUX 10.20.
* gnulib/m4/vasnprintf.m4: Likewise.

* docs/libvir.html docs/format.html: fixes the examples on the
  section about ethernet bridging, as raised by Maxwell Bottiger,
  fixes bug #430790
Daniel

* src/internal.h: move xstrol() variants from here ...

* src/util.[ch]: ... to here and rename to virStrToLong()

* src/libvirt_sym.version: export __virStrToLong_i() for
virsh and qemud.

* src/nodeinfo.c, src/stats_linux.c, src/virsh.c,
  src/xend_internal.c, qemud/qemud.c: replace xstrtol()
calls with virStrToLong()

* src/nodeinfo.h: don't include internal.h, which was only
needed for xstrtol(), but instead include libvirt.h which
is suffificient for the declarations in the header.

* Makefile.cfg (local-checks-to-skip): Remove sc_no_have_config_h.
* qemud/mdns.c: Remove "#ifdef HAVE_CONFIG_H".
* Makefile.maint (sc_no_have_config_h): Tighten up regexp,
so that the above mention of "HAVE_CONFIG_H" doesn't match.
* .x-sc_no_have_config_h: New file, to exempt gnulib/ straggler.

* qemud/remote.c: fix a missing ')' introduced earlier
Daniel

* src/hash.c: fix a couple of problems in virHashRemoveSet based
  on Hiroyuki Kaguchi patch and explanations.
Daniel