Replace FileInputStream and FileOutputStream by their JDK7 equivalents

[lbruun]

Files.newInputStream() and Files.newOutputStream() are generally preferred over new FileInputStream() and new FileOutputStream().

The reason is is that FileInputStream and FileOutputStream have finalizers and therefore puts pressure on the GC. The finalizers will make sure the file descriptor is actually released if the developer has forgotten to explicitly close the fis or fos. But if this is taken care of, then there's no need to have the overhead that use of fis or fos implies.

It is not in all cases that a fis or a fos can be replaced with the JDK7 equivalents from Files class. But in the cases where the fis or fos doesn't escape the method then it can always be replaced and the hint would apply.

[markiewb]

@lbruun: Good idea, but I do not actively support this plugin anymore. Nevertheless you could provide a pull-request, which I will merge. See the existing classes and the tests to get started.