Update ClassFile.java

InputStream.read() does not guarantee actually, well, reading anything:

http://docs.oracle.com/javase/6/docs/api/java/io/InputStream.html#read(byte[])

The original code failed for me when reading from a `.jar` file, as InputStream.read() would cut out halfway and leave the rest of the `data` array as zeroes. This cause a NPE in `resolveFromClassFile`:

```
Exception in thread "main" java.lang.NullPointerException
	at soot.coffi.method_info.toName(method_info.java:86)
	at soot.coffi.Util.resolveFromClassFile(Util.java:225)
	at soot.CoffiClassSource.resolve(CoffiClassSource.java:39)
	at soot.coffi.Test$.loadClass(Test.scala:22)
	at soot.coffi.Test$.main(Test.scala:27)
	at soot.coffi.Test.main(Test.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
```

Wrapping it in a DataInputStream fixes that problem on my machine, and should have no affect otherwise
Fix for #59 as suggested by Tony Yan
Merge pull request #60 from malaverdiere/my-develop

Fix for #59 as suggested by Tony Yan. Thanks!
Merge pull request #58 from lihaoyi/patch-1

ClassFile.loadClass is buggy, will only read part of the file
added handling of class constants in constant evaluator
removed a debug method message printed out unconditionally which bloated stdout to several hundred MB for large Android apps
removed more internal debugging outputs bloating stdout
#1: removed another unconditional debug output bloating stdout
#2: cleaned a Java warning
extended the Jimple-based backwards icfg to be bidirectional
Adding links to the jasmin and heros github projects.
removed a too restricting "final" modifier at a method
Merge branch 'develop' of github.com:Sable/soot into develop
resolved Java warnings
added an assertion to check early whether we are working on broken code. Makes resolving issues way easier
added default case for dynamic invoke expressions
removed unused variable
eliminated unnecessary second hash computation
added support for inlined zero constants to DexNullTransformer.java
DexNullTransformer.java now also supporting typecasts and return statements for inlined zero constants
enhanced the DexNullTransformer.java TO correctly handle object arrays

fixed retyping to filter out statements which have been removed from the body in the meantime