[VOL-5545] Update voltha docs

- release notes for VOLTHA versions 2.6 to 2.15 with new Jira links and adjust release schedule details
- update old links
- remove ONF references and links
- update e-mail links
- update copright notices

Change-Id: Id6be18986a8f52f2dfcc07e2b0d2efcb0ae1c0e4
Signed-off-by: serkant.uluderya <serkant.uluderya@netsia.com>
diff --git a/VERSION b/VERSION
index cb43758..575a07b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.13.5-dev
+2.14.0
\ No newline at end of file