Merge pull request #324 from jam7/llvm-crew_dest_dir

change to use CREW_DEST_DIR in llvm.rb

packages/llvm.rb

 require 'package'
 
 class Llvm < Package
-  version '3.8.1'
+  version '3.8.1-1'
   source_url 'http://llvm.org/releases/3.8.1/llvm-3.8.1.src.tar.xz'
   source_sha1 'e0c48c4c182424b99999367d688cd8ce7876827b'
 
@@ -18,7 +18,7 @@ class Llvm < Package
 
   def self.install
     Dir.chdir CREW_BREW_DIR+"llvm-"+version+".src/mybuilddir" do
-       system "cmake -DCMAKE_INSTALL_PREFIX=/usr/local -P cmake_install.cmake"
+       system "cmake -DCMAKE_INSTALL_PREFIX=#{CREW_DEST_DIR}/usr/local -P cmake_install.cmake"
     end  
   end
 end