changelog: Convert it to pretty rst

It was reStructuredText already, but links showing was ugly, especially
when there were several links in the same line.

Use kernelnewbies style to refer to commits, when particular commit url
is not shown to user, only hyperlinked. This way it looks nicer.

CHANGELOG

@@ -4,25 +4,31 @@ Wendelin.core change history
 0.4 (2015-08-19)
 ----------------
 
-- Add support for O(δ) in-place BigArray.append()
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/1245acc9
+- Add support for O(δ) in-place BigArray.append() (commit__)
 
-- Implement proper multithreading support
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/d53271b9
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/1245acc9
+
+- Implement proper multithreading support (commit__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/d53271b9
 
 - Implement proper RAM pages invalidation when backing ZODB objects are changed
-  from outside
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/cb779c7b
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/92bfd03e
+  from outside (`commit 1`__, 2__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/cb779c7b
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/92bfd03e
 
 - Fix all kind of failures that could happen when ZODB connection changes
-  worker thread in-between handling requests
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/c7c01ce4
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/64d1f40b
+  worker thread in-between handling requests (`commit 1`__, 2__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/c7c01ce4
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/64d1f40b
 
 - Tox tests now cover usage with FileStorage, ZEO and NEO ZODB storages
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/010eeb35
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/7fc4ec66
+  (`commit 1`__, 2__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/010eeb35
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/7fc4ec66
 
 - Various bugfixes
 
@@ -40,7 +46,9 @@ Wendelin.core change history
   either succeeds, or raises MemoryError if not enough address space is
   available to cover whole A. (current limitation is ~ 127TB on linux/amd64)
 
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/00db08d6
+  (commit__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/00db08d6
 
 - Various bugfixes (build-fixes, crashes, overflows, etc)
 
@@ -48,8 +56,9 @@ Wendelin.core change history
 0.2 (2015-05-25)
 ----------------
 
-- Add support for O(1) in-place BigArray.resize()
-  https://lab.nexedi.com/nexedi/wendelin.core/commit/ca064f75
+- Add support for O(1) in-place BigArray.resize() (commit__)
+
+  __ https://lab.nexedi.com/nexedi/wendelin.core/commit/ca064f75
 
 - Various build bugfixes (older systems, non-std python, etc)