Updates VERSION and Changelog files for the master branch.

Changelog

@@ -13,6 +13,11 @@
 # '#?nnn'  : OLD-BTS entry #nnn                                               #
 ###############################################################################
 
+##################################
+Open Source Release <next-release>
+##################################
+
+
 ################################
 Open Source Release 18.0 (Argon)
 ################################

VERSION

-18.0
\ No newline at end of file
+18.0+dev
\ No newline at end of file

tests/misc/oracle/debug_category.16.res.oracle

@@ -9,7 +9,7 @@
   
   Plug-in test aborted: internal error.
   Please report as 'crash' at http://bts.frama-c.com/.
-  Your Frama-C version is 18.0 (Argon).
+  Your Frama-C version is 18.0+dev (Argon).
   Note that a version and a backtrace alone often do not contain enough
   information to understand the bug. Guidelines for reporting bugs are at:
   http://bts.frama-c.com/dokuwiki/doku.php?id=mantis:frama-c:bug_reporting_guidelines

tests/misc/oracle/log-file.1.res.oracle

@@ -14,7 +14,7 @@
   
   Frama-C aborted: internal error.
   Please report as 'crash' at http://bts.frama-c.com/.
-  Your Frama-C version is 18.0 (Argon).
+  Your Frama-C version is 18.0+dev (Argon).
   Note that a version and a backtrace alone often do not contain enough
   information to understand the bug. Guidelines for reporting bugs are at:
   http://bts.frama-c.com/dokuwiki/doku.php?id=mantis:frama-c:bug_reporting_guidelines

tests/misc/oracle/plugin-log-all.txt

@@ -14,7 +14,7 @@ The full backtrace is:
 
 Frama-C aborted: internal error.
 Please report as 'crash' at http://bts.frama-c.com/.
-Your Frama-C version is 18.0 (Argon).
+Your Frama-C version is 18.0+dev (Argon).
 Note that a version and a backtrace alone often do not contain enough
 information to understand the bug. Guidelines for reporting bugs are at:
 http://bts.frama-c.com/dokuwiki/doku.php?id=mantis:frama-c:bug_reporting_guidelines