Drop Python 2.6 support

See PR #1366 and PR #1390 for a thorough explanation.

docs/changelog.rst

@@ -66,6 +66,8 @@ Features:
 
 Core changes:
 
+* Python 2.6 support has been dropped. This was the occasion to remove several
+  hacks and workarounds.
 * The ``tracktotal`` attribute is now a *track-level field* instead of an
   album-level one. This field stores the total number of tracks on the
   album, or if the :ref:`per_disc_numbering` config option is set, the total

docs/guides/main.rst

@@ -9,13 +9,13 @@ collection better.
 Installing
 ----------
 
-You will need Python. (Beets is written for `Python 2.7`_, but it works with
-2.6 as well. Python 3.x is not yet supported.)
+You will need Python. (Beets is written for `Python 2.7`_. 2.6 support has been
+dropped, and Python 3.x is not yet supported.)
 
 .. _Python 2.7: http://www.python.org/download/
 
 * **Mac OS X** v10.7 (Lion) and 10.8 (Mountain Lion) include Python 2.7 out of
-  the box; Snow Leopard ships with Python 2.6.
+  the box; Snow Leopard ships with Python 2.6 so you will need to upgrade it.
 
 * On **Debian or Ubuntu**, depending on the version, beets is available as an
   official package (`Debian details`_, `Ubuntu details`_), so try typing:

setup.py

@@ -118,7 +118,6 @@ setup(
         'Environment :: Console',
         'Environment :: Web Environment',
         'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
     ],
 )

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py26, py27, pypy, docs, flake8
+envlist = py27, pypy, docs, flake8
 
 [testenv]
 deps =
@@ -19,11 +19,6 @@ deps =
 commands =
     nosetests {posargs}
 
-[testenv:py26]
-deps =
-    {[testenv]deps}
-    unittest2
-
 [testenv:py27cov]
 basepython = python2.7
 deps =