Add mingw. Remove some unneeded projects.

There's probably more in here we don't need. Will clean up more later.
diff --git a/default.xml b/default.xml
index 1dd0728..b4f2c1c 100644
--- a/default.xml
+++ b/default.xml
@@ -8,21 +8,15 @@
            remote="aosp"
            sync-j="4" />
 
-  <project path="ndk" name="platform/ndk" />
-  <project path="prebuilts/gcc/darwin-x86/host/headers" name="platform/prebuilts/gcc/darwin-x86/host/headers" groups="pdk,darwin" />
-  <project path="prebuilts/gcc/darwin-x86/host/i686-apple-darwin-4.2.1" name="platform/prebuilts/gcc/darwin-x86/host/i686-apple-darwin-4.2.1" groups="pdk,darwin" />
   <project path="prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8" name="platform/prebuilts/gcc/linux-x86/host/x86_64-linux-glibc2.11-4.8" groups="pdk,linux" />
-  <project path="prebuilts/ndk" name="platform/prebuilts/ndk" revision="dev" groups="pdk" />
   <project path="toolchain/binutils" name="toolchain/binutils" />
-  <project path="toolchain/build" name="toolchain/build" />
   <project path="toolchain/cloog" name="toolchain/cloog" />
-  <project path="toolchain/expat" name="toolchain/expat" />
   <project path="toolchain/gcc" name="toolchain/gcc" />
   <project path="toolchain/gmp" name="toolchain/gmp" />
   <project path="toolchain/isl" name="toolchain/isl" />
+  <project path="toolchain/mingw" name="toolchain/mingw" />
   <project path="toolchain/mpc" name="toolchain/mpc" />
   <project path="toolchain/mpfr" name="toolchain/mpfr" />
   <project path="toolchain/ppl" name="toolchain/ppl" />
-  <project path="toolchain/sed" name="toolchain/sed" />
 
 </manifest>