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, 70 insertions, 0 deletions

diff --git a/lib/transfer.h b/lib/transfer.h
new file mode 100644
index 000000000..b47422a63
--- /dev/null
+++ b/lib/transfer.h
@@ -0,0 +1,70 @@
+#ifndef HEADER_CURL_TRANSFER_H
+#define HEADER_CURL_TRANSFER_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2011, 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.
+ *
+ ***************************************************************************/
+CURLcode Curl_perform(struct SessionHandle *data);
+CURLcode Curl_pretransfer(struct SessionHandle *data);
+CURLcode Curl_second_connect(struct connectdata *conn);
+CURLcode Curl_posttransfer(struct SessionHandle *data);
+
+typedef enum {
+  FOLLOW_NONE,  /* not used within the function, just a placeholder to
+                   allow initing to this */
+  FOLLOW_FAKE,  /* only records stuff, not actually following */
+  FOLLOW_RETRY, /* set if this is a request retry as opposed to a real
+                          redirect following */
+  FOLLOW_REDIR, /* a full true redirect */
+  FOLLOW_LAST   /* never used */
+} followtype;
+
+CURLcode Curl_follow(struct SessionHandle *data, char *newurl,
+                     followtype type);
+
+
+CURLcode Curl_readwrite(struct connectdata *conn, bool *done);
+int Curl_single_getsock(const struct connectdata *conn,
+                        curl_socket_t *socks,
+                        int numsocks);
+CURLcode Curl_readrewind(struct connectdata *conn);
+CURLcode Curl_fillreadbuffer(struct connectdata *conn, int bytes, int *nreadp);
+CURLcode Curl_reconnect_request(struct connectdata **connp);
+CURLcode Curl_retry_request(struct connectdata *conn, char **url);
+bool Curl_meets_timecondition(struct SessionHandle *data, time_t timeofdoc);
+
+/* This sets up a forthcoming transfer */
+void
+Curl_setup_transfer (struct connectdata *data,
+               int sockindex,           /* socket index to read from or -1 */
+               curl_off_t size,         /* -1 if unknown at this point */
+               bool getheader,          /* TRUE if header parsing is wanted */
+               curl_off_t *bytecountp,  /* return number of bytes read */
+               int writesockindex,      /* socket index to write to, it may
+                                           very well be the same we read from.
+                                           -1 disables */
+               curl_off_t *writecountp /* return number of bytes written */
+);
+
+long Curl_sleep_time(curl_off_t rate_bps, curl_off_t cur_rate_bps,
+                     int pkt_size);
+
+#endif /* HEADER_CURL_TRANSFER_H */
+