Merge branch 'rr/triangle'

Support "pull from one place, push to another place" workflow
better by introducing remote.pushdefault (overrides the "origin"
thing) and branch.*.pushremote (overrides the branch.*.remote).

* rr/triangle:
remote.c: introduce branch.<name>.pushremote
remote.c: introduce remote.pushdefault
remote.c: introduce a way to have different remotes for fetch/push
t5516 (fetch-push): drop implicit arguments from helper functions
t5516 (fetch-push): update test description
remote.c: simplify a bit of code using git_config_string()

diff --cc t/t5516-fetch-push.sh
index 32ad89107b20fc2187b416bc7e3f4d45e17474c6,7bf1555cacabdfaf0a2cce804c1b08e85bdce02b..838e71dafea8388cbe18c82b26f58f074f56abbd
--- 1/t/t5516-fetch-push.sh
--- 2/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@@ -216,11 -235,11 +235,11 @@@ test_expect_success 'push with pushInst
  '
  
  test_expect_success 'push with pushInsteadOf and explicit pushurl (pushInsteadOf should not rewrite)' '
-       mk_empty &&
+       mk_empty testrepo &&
 -      TRASH="$(pwd)/" &&
 -      test_config "url.trash2/.pushInsteadOf" trash/ &&
 +      test_config "url.trash2/.pushInsteadOf" testrepo/ &&
 +      test_config "url.trash3/.pusnInsteadOf" trash/wrong &&
        test_config remote.r.url trash/wrong &&
 -      test_config remote.r.pushurl "$TRASH/testrepo" &&
 +      test_config remote.r.pushurl "testrepo/" &&
        git push r refs/heads/master:refs/remotes/origin/master &&
        (
                cd testrepo &&