Download all versions of the xflux binary

To make it easier to test if you're experiencing the dreaded
Issue #27.

And make the magic numbers less magic.

.gitignore

@@ -4,3 +4,5 @@ dist/
 build/
 /xflux
 /installed.txt
+/xflux11
+/xflux12

download-xflux.py

@@ -1,19 +1,26 @@
+#!/usr/bin/env python3
+
 from sys import maxsize
 import subprocess
 
 # There is similar code in ./debian/postinst. If you are changing this
 # you probably want to change that too.
 def download_xflux():
     # Determines which is the appropriate executable for 32-bit
-    if maxsize == 2147483647:
+    if maxsize == 2**31 - 1:
         print("Downloading 32-bit xflux ...")
-        url = "https://justgetflux.com/linux/xflux-pre.tgz"
-    elif maxsize == 9223372036854775807:
+        urls = ["https://justgetflux.com/linux/xflux-pre.tgz"]
+    elif maxsize == 2**63 - 1:
         print("Downloading 64-bit xflux ...")
-        url = "https://justgetflux.com/linux/xflux64.tgz"
-    tarchive = "/tmp/xflux.tgz"
-    subprocess.call(['wget', url, '-O', tarchive])
-    subprocess.call(['tar', '-xvf', tarchive])
+        urls = ["https://justgetflux.com/linux/xflux64.tgz",
+                "https://justgetflux.com/linux/xflux11.tgz",
+                "https://justgetflux.com/linux/xflux12.tgz"]
+    else:
+        raise Exception("Unexpected maxsize = %i!" % maxsize)
+    for url in urls:
+        tarchive = "/tmp/xflux.tgz"
+        subprocess.call(['wget', url, '-O', tarchive])
+        subprocess.call(['tar', '-xvf', tarchive])
 
 if __name__ == '__main__':
     download_xflux()