Don't use the "soft" magic db

It doesn't help us determine if the file is binary or not, and just
seems to create a bunch of problems like the ones in #4

ext/charlock_holmes/encoding_detector.c

@@ -274,15 +274,11 @@ static VALUE rb_encdec__alloc(VALUE klass)
 		rb_raise(rb_eStandardError, "%s", u_errorName(status));
 	}
 
-	detector->magic = magic_open(0);
+	detector->magic = magic_open(MAGIC_NO_CHECK_SOFT);
 	if (detector->magic == NULL) {
 		rb_raise(rb_eStandardError, "%s", magic_error(detector->magic));
 	}
 
-	// load the libmagic database
-	// NULL means use the default or whatever is specified by the MAGIC env var
-	magic_load(detector->magic, NULL);
-
 	return obj;
 }
 

ext/charlock_holmes/extconf.rb

@@ -58,6 +58,7 @@ def sys(cmd)
   sys("tar zxvf #{src}")
   Dir.chdir(dir) do
     sys("./configure --prefix=#{CWD}/dst/ --disable-shared --enable-static --with-pic")
+    sys("patch -p0 < ../file-soft-check.patch")
     sys("make -C src install")
     sys("make -C magic install")
   end

ext/charlock_holmes/src/file-soft-check.patch

@@ -0,0 +1,11 @@
+--- src/funcs.c.orig	2013-01-27 01:23:01.000000000 -0800
++++ src/funcs.c	2013-01-27 01:23:46.000000000 -0800
+@@ -300,7 +300,7 @@
+ protected int
+ file_reset(struct magic_set *ms)
+ {
+-	if (ms->mlist == NULL) {
++	if (!(ms->flags & MAGIC_NO_CHECK_SOFT) &&  ms->mlist == NULL) {
+ 		file_error(ms, 0, "no magic files loaded");
+ 		return -1;
+ 	}