Python: move interpreters

Move Python interpreters (CPython, PyPy) to same folder and share
layout.

pkgs/development/interpreters/python/cpython/2.7/2.7.3-getpath-exe-extension.patch

@@ -0,0 +1,31 @@
+--- origsrc/Modules/getpath.c.orig	2012-11-27 12:07:56.098645900 -0500
++++ src/Modules/getpath.c	2012-11-27 12:10:11.254895900 -0500
+@@ -436,6 +436,28 @@
+                         if (isxfile(progpath))
+                                 break;
+ 
++#ifdef __CYGWIN__
++                        /*
++                         * Cygwin automatically removes the ".exe" extension from argv[0]
++                         * to make programs feel like they are in a more Unix-like
++                         * environment.  Unfortunately, this can make it problemmatic for
++                         * Cygwin to distinguish between a directory and an executable with
++                         * the same name excluding the ".exe" extension.  For example, the
++                         * Cygwin Python build directory has a "Python" directory and a
++                         * "python.exe" executable.  This causes isxfile() to erroneously
++                         * return false.  If isdir() returns true and there is enough space
++                         * to append the ".exe" extension, then we try again with the
++                         * extension appended.
++                         */
++#define EXE ".exe"
++                        if (isdir(progpath) && strlen(progpath) + strlen(EXE) <= MAXPATHLEN)
++                        {
++                            strcat(progpath, EXE);
++                            if (isxfile(progpath))
++                                break;
++                        }
++#endif /* __CYGWIN__ */
++
+                         if (!delim) {
+                                 progpath[0] = '\0';
+                                 break;