Add sre_compile_test.expected

Ie, manually specify the reference output for sre_compile_test.py instead
of running CPython to generate it.  CPython changed the behavior (and interface)
of _optimize_charset at some point between 2.7.7 (where we copied from) and
2.7.9.

We should probably copy their new implementation (seems to have a few more
optimizations), but for now this should fix #707.

test/tests/sre_compile_test.expected

+None
+None
+('b',)
+0
+10000
+20000
+30000
+40000
+50000
+60000
+70000
+80000
+90000
+[('bigcharset', [2, 16843008L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 16843009L, 0L, 0L, 0L, 0L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L, 4294967295L])]

test/tests/sre_compile_test.py

@@ -15,4 +15,7 @@ def identity(o):
 
 charset = [(sre_constants.RANGE, (128, 65535))]
 
+# Note: _optimize_charset changed behavior + interface some time
+# between 2.7.7 (our stdlib) and 2.7.9 (current cpython latest),
+# so this test has a .expected file to avoid running cpython.
 print sre_compile._optimize_charset(charset, identity)