Don't hardcode 'gcc' in manual formulas.

Formula/dos2unix.rb

@@ -7,8 +7,11 @@ class Dos2unix <Formula
 
   def install
     File.unlink 'dos2unix'
+
     # we don't use make as it doesn't optimise :P
-    system "gcc #{ENV['CFLAGS']} dos2unix.c -o dos2unix"
+    gcc = ENV['CC'] || "gcc"
+    system "#{gcc} #{ENV['CFLAGS']} dos2unix.c -o dos2unix"
+
     # make install is broken due to INSTALL file, but also it sucks so we'll do it
     # also Ruby 1.8 is broken, it won't allow you to move a symlink that's
     # target is invalid. FFS very dissapointed with dependability of 

Formula/tree.rb

@@ -6,7 +6,9 @@ class Tree <Formula
   @md5='a7731a898e2c0d7e422a57a84ffbb06c'
 
   def install
-    system "gcc #{ENV['CFLAGS']} -o tree tree.c strverscmp.c"
+    gcc = ENV['CC'] || "gcc"
+    system "#{gcc} #{ENV['CFLAGS']} -o tree tree.c strverscmp.c"
+
     bin.install "tree"
     man1.install "man/tree.1"
   end