Added VERSIONS that explains about the (lib)curl version numbers

docs/Makefile.am

@@ -61,7 +61,7 @@ HTMLPAGES = \
 EXTRA_DIST = $(man_MANS) \
 	MANUAL BUGS CONTRIBUTE FAQ FEATURES INTERNALS \
 	README.win32 RESOURCES TODO TheArtOfHttpScripting THANKS \
-	$(HTMLPAGES)
+	VERSIONS $(HTMLPAGES)
 
 MAN2HTML= gnroff -man $< | man2html >$@
 

docs/VERSIONS

+                                  _   _ ____  _     
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+                             / __| | | | |_) | |    
+                            | (__| |_| |  _ <| |___ 
+                             \___|\___/|_| \_\_____|
+
+Version Numbers and Releases
+
+ Curl is not only curl. Curl is also libcurl. They're actually individually
+ versioned, but they mostly follow each other rather closely.
+
+ The version numbering is always built up using the same system:
+
+        X.Y[.Z][-preN]
+
+ Where
+   X is main version number
+   Y is release number
+   Z is patch number
+   N is pre-release number
+
+ One of these numbers will get bumped in each new release. The numbers to the
+ right of a bumped number will be reset to zero. If Z is zero, it is not
+ included in the version number. The pre release number is only included in
+ pre releases (they're never used in public, official, releases).
+
+ The main version number will get bumped when *really* big, world colliding
+ changes are made. The release number is bumped when big changes are
+ performed. The patch number is bumped when the changes are mere bugfixes and
+ only minor feature changes. The pre-release is a counter, to identify which
+ pre-release a certain release is.
+
+ When reaching the end of a pre-release period, the version without the
+ pre-release part will be released as a public release.
+
+ It means that after release 1.2.3, we can release 2.0 if something really big
+ has been made, 1.3 if not that big changes were made or 1.2.4 if mostly bugs
+ were fixed. Before 1.2.4 is released, we might release a 1.2.4-pre1 release
+ for the brave people to try before the actual release.
+
+ Bumping, as in increasing the number with 1, is unconditionally only
+ affecting one of the numbers (except the ones to the right of it, that may be
+ set to zero). 1 becomes 2, 3 becomes 4, 9 becomes 10, 88 becomes 89 and 99
+ becomes 100. So, after 1.2.9 comes 1.2.10. After 3.99.3, 3.100 might come.
+
+ All original curl source release archives are named according to the libcurl
+ version (not according to the curl client version that, as said before, might
+ differ).
+
+ As a service to any application that might want to support new libcurl
+ features while still being able to build with older versions, all releases
+ have the libcurl version stored in the curl/curl.h file using a static
+ numbering scheme that can be used for comparison. The version number is
+ defined as:
+        
+        #define LIBCURL_VERSION_NUM 0xXXYYZZ
+
+ Where XX, YY and ZZ are the main version, release and patch numbers in
+ hexadecimal. All three numbers are always represented using two digits.  1.2
+ would appear as "0x010200" while version 9.11.7 appears as "0x090b07".
+
+ This 6-digit hexadecimal number does not show pre-release number, and it is
+ always a greater number in a more recent release. It makes comparisons with
+ greater than and less than work.