Revert changes relative to lib/*.[ch] recent renaming

This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:

  f871de0... build: make use of 76 lib/*.h renamed files
  ffd8e12... build: rename 76 lib/*.h files

This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:

  c087374... curl_setup.h: remove redundant include guard

This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:

  13606bb... build: make use of 93 lib/*.c renamed files
  5b6e792... build: rename 93 lib/*.c files
  7d83dff... build: commit 13606bbfde follow-up 1

Start of related discussion thread:

  http://curl.haxx.se/mail/lib-2013-01/0012.html

Asking for confirmation on pushing this revertion commit:

  http://curl.haxx.se/mail/lib-2013-01/0048.html

Confirmation summary:

  http://curl.haxx.se/mail/lib-2013-01/0079.html

NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.

  lib/curl_imap.h
  lib/curl_smtp.h

1 files changed, 91 insertions, 0 deletions

diff --git a/lib/nonblock.c b/lib/nonblock.c
new file mode 100644
index 000000000..a2722ed7f
--- /dev/null
+++ b/lib/nonblock.c
@@ -0,0 +1,91 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "setup.h"
+
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#if (defined(HAVE_IOCTL_FIONBIO) && defined(NETWARE))
+#include <sys/filio.h>
+#endif
+#ifdef __VMS
+#include <in.h>
+#include <inet.h>
+#endif
+
+#include "nonblock.h"
+
+/*
+ * curlx_nonblock() set the given socket to either blocking or non-blocking
+ * mode based on the 'nonblock' boolean argument. This function is highly
+ * portable.
+ */
+int curlx_nonblock(curl_socket_t sockfd,    /* operate on this */
+                   int nonblock   /* TRUE or FALSE */)
+{
+#if defined(USE_BLOCKING_SOCKETS)
+
+  return 0; /* returns success */
+
+#elif defined(HAVE_FCNTL_O_NONBLOCK)
+
+  /* most recent unix versions */
+  int flags;
+  flags = sfcntl(sockfd, F_GETFL, 0);
+  if(nonblock)
+    return sfcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
+  else
+    return sfcntl(sockfd, F_SETFL, flags & (~O_NONBLOCK));
+
+#elif defined(HAVE_IOCTL_FIONBIO)
+
+  /* older unix versions */
+  int flags = nonblock ? 1 : 0;
+  return ioctl(sockfd, FIONBIO, &flags);
+
+#elif defined(HAVE_IOCTLSOCKET_FIONBIO)
+
+  /* Windows */
+  unsigned long flags = nonblock ? 1UL : 0UL;
+  return ioctlsocket(sockfd, FIONBIO, &flags);
+
+#elif defined(HAVE_IOCTLSOCKET_CAMEL_FIONBIO)
+
+  /* Amiga */
+  long flags = nonblock ? 1L : 0L;
+  return IoctlSocket(sockfd, FIONBIO, flags);
+
+#elif defined(HAVE_SETSOCKOPT_SO_NONBLOCK)
+
+  /* BeOS */
+  long b = nonblock ? 1L : 0L;
+  return setsockopt(sockfd, SOL_SOCKET, SO_NONBLOCK, &b, sizeof(b));
+
+#else
+#  error "no non-blocking method was found/used/set"
+#endif
+}