Remove Tango patch that's been applied upstream.

tango.patch

@@ -1,56 +0,0 @@
-Index: lib/unittest.sh
-===================================================================
---- lib/unittest.sh	(revision 4330)
-+++ lib/unittest.sh	(working copy)
-@@ -15,14 +15,14 @@
- usage() {
-     echo 'Usage: ./unittest.sh [otions ...]
- Options:
--  --help: This message
-+  --help:    This message
-   --run-all: Reports result instead of breaking. Do not use this if you want to
--         run unittest runner through a debugger.
--  dmd:    Builds unittests for dmd
--  gdc:    Builds unittests for gdc
--  ldc: Builds unittests for ldc
-+             run unittest runner through a debugger.
-+  dmd:       Builds unittests for dmd
-+  gdc:       Builds unittests for gdc
-+  ldc:       Builds unittests for ldc
- 
--  <none>: Builds unittests for all known compilers.'
-+  <none>:    Builds unittests for all known compilers.'
-   exit 0
- }
- 
-@@ -37,7 +37,7 @@
- 
-     rebuild --help >& /dev/null || die "rebuild required, aborting" 1
- 
--    if ! $DC --help >& /dev/null
-+    if ! which $DC >& /dev/null
-     then
-         echo "$DC not found on your \$PATH!"
-     else
-Index: lib/build-tango.sh
-===================================================================
---- lib/build-tango.sh	(revision 4330)
-+++ lib/build-tango.sh	(working copy)
-@@ -131,7 +131,7 @@
-     DC=$1
-     LIB=$2
- 
--    if ! $DC --help >& /dev/null
-+    if ! which "$DC" >& /dev/null
-     then
-         echo "$DC not found on your \$PATH!"
-         return
-@@ -203,7 +203,7 @@
-             build gdmd libgtango.a libgphobos.a
-             ;;
-         ldc)
--            build ldc libtango-user-ldc.a build-tango.sh
-+            build ldmd libtango-user-ldc.a build-tango.sh
-             ;;
-         mac)
-             POSIXFLAG="-version=Posix"