2018-01-02, Version 6.12.3 'Boron' (LTS)

Notable Changes:

* build:
  - configure can now be run from any directory (Gibson Fahnestock)
    #17321

PR-URL: #17776

CHANGELOG.md

@@ -26,7 +26,8 @@ release.
 </tr>
 <tr>
   <td valign="top">
-<b><a href="doc/changelogs/CHANGELOG_V6.md#6.12.2">6.12.2</a></b><br/>
+<b><a href="doc/changelogs/CHANGELOG_V6.md#6.12.3">6.12.3</a></b><br/>
+<a href="doc/changelogs/CHANGELOG_V6.md#6.12.2">6.12.2</a><br/>
 <a href="doc/changelogs/CHANGELOG_V6.md#6.12.1">6.12.1</a><br/>
 <a href="doc/changelogs/CHANGELOG_V6.md#6.12.0">6.12.0</a><br/>
 <a href="doc/changelogs/CHANGELOG_V6.md#6.11.5">6.11.5</a><br/>