tlsdated: support command-line proxy override

This makes a proxy passed on the command line with -x supplant proxies for
configured sources, and makes the 'proxy' stanza in sources optional (in which
case we supply no proxy argument for them).

Signed-off-by: Elly Fong-Jones <[email protected]>
diff --git a/CHANGELOG b/CHANGELOG
index 3531b1e..267f79b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+0.0.7 TBD
+  Add -x option to tlsdated to override source proxies.
 0.0.6 Mon 18 Feb, 2013
   Ensure that tlsdate compiles with g++ by explicit casting rather than
   implicit casting by whatever compiler is compiling tlsdate.