Change the version string from "2.2+" to "2.3a0". disutils peels off

the first 3 characters of this string in several places, so for as long
as they remain "2.2" it confuses the heck out of attempts to build 2.3
stuff using distutils.

Include/patchlevel.h

@@ -26,7 +26,7 @@
 #define PY_RELEASE_SERIAL	1
 
 /* Version as a string */
-#define PY_VERSION		"2.2+"
+#define PY_VERSION		"2.3a0"
 
 /* Version as a single 4-byte hex number, e.g. 0x010502B2 == 1.5.2b2.
    Use this for numeric comparisons, e.g. #if PY_VERSION_HEX >= ... */