Use ENV.make_jobs in formulae

Some formulae are still calling Hardware.processor_count; replace those
instances with ENV.make_jobs.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>

Formula/boost.rb

@@ -57,7 +57,7 @@ class Boost < Formula
 
     args = ["--prefix=#{prefix}",
             "--libdir=#{lib}",
-            "-j#{Hardware.processor_count}",
+            "-j#{ENV.make_jobs}",
             "--layout=tagged",
             "--user-config=user-config.jam",
             "threading=multi",

Formula/csstidy.rb

@@ -8,7 +8,7 @@ class Csstidy < Formula
 
   def install
     arch = Hardware.is_64_bit? ? 'x64' : 'ia32'
-    system "scons", "-j #{Hardware.processor_count}",
+    system "scons", "-j #{ENV.make_jobs}",
                     "arch=#{arch}"
 
     bin.install "release/csstidy/csstidy"

Formula/ledger.rb

@@ -19,7 +19,7 @@ class Ledger < Formula
     else
       # gmp installs x86_64 only
       inreplace 'acprep', "'-arch', 'i386', ", "" if Hardware.is_64_bit?
-      system "./acprep -j#{Hardware.processor_count} opt make -- --prefix=#{prefix}"
+      system "./acprep -j#{ENV.make_jobs} opt make -- --prefix=#{prefix}"
     end
     system 'make'
     ENV.deparallelize

Formula/mkvtoolnix.rb

@@ -17,7 +17,7 @@ class Mkvtoolnix < Formula
                           "--prefix=#{prefix}",
                           "--with-boost-libdir=#{HOMEBREW_PREFIX}/lib", # For non-/usr/local prefix
                           "--with-boost-regex=boost_regex-mt" # via macports
-    system "./drake -j#{Hardware.processor_count}"
+    system "./drake -j#{ENV.make_jobs}"
     system "./drake install"
   end
 end

Formula/v8.rb

@@ -9,7 +9,7 @@ class V8 < Formula
   def install
     arch = Hardware.is_64_bit? ? 'x64' : 'ia32'
 
-    system "scons", "-j #{Hardware.processor_count}",
+    system "scons", "-j #{ENV.make_jobs}",
                     "arch=#{arch}",
                     "mode=release",
                     "snapshot=on",

Formula/v8cgi.rb

@@ -33,7 +33,7 @@ class V8cgi < Formula
     args << (ARGV.include? '--with-sqlite') ? 'sqlite=1' : 'sqlite=0'
 
     system "scons",
-            "-j #{Hardware.processor_count}",
+            "-j #{ENV.make_jobs}",
             "arch=#{arch}",
             "library=shared",
             "socket=1",