Moving to a new release numbering regime

This is release 2.6.0

For future releases we will include more information about what has
changed since the last release.

doc/WhatsNew.rst

@@ -2,6 +2,17 @@
 What's New in Ginga?
 ++++++++++++++++++++
 
+Ver 2.6.0 (2016-11-16)
+======================
+With release 2.6.0 we are moving to a new versioning scheme that makes
+use of github tagged releases and a "dev" versioning scheme for updates
+between releases.
+
+This release includes many bugfixes and improvements, new canvas types
+(XRange and YRange), a Command plugin, WCSMatch plugin, dynamically
+configurable workspaces, OpenCv acceleration, an HTML5 backend and much
+much more.
+
 Ver 2.2.20160505170200
 ======================
 Ginga has merged the astropy-helpers template.  This should make it more

setup.cfg

@@ -26,7 +26,7 @@ license = BSD
 url = http://ejeschke.github.com/ginga
 edit_on_github = False
 github_project = ejeschke/ginga/
-version = 2.5.20161113213300
+version = 2.6.0
 keywords = scientific image viewer numpy toolkit astronomy FITS
 classifiers =
     Intended Audience :: Science/Research,