Initial webrev with changes for JDK 9

[Xueming Shen]

jar.Main: comments

(1) InputstreamSupplier:
      since what we really need here is the byte[], maybe just go straightforward
      to use InputStream/Files.(path)readAllBytes() ?

(2) #273 don't the "moduleInfo" used for consistency check the same one as
      the used for updating at #244? can't be shared?

(3) if it was me I would simply have passed the "moduleInfoBytes" around as
      a byte[], we might not even need this "InputStreamSupplier" interface.

(4) printModuleDescriptor: for a "file" jar, it might be much faster to open the
      zip file with a ZipFile, then entry -> input stream. otherwise, the ZIS might
      be very slow if it's a big jar and the descriptor file is at the end of the file.

(5) hashDependences:
       "matcher" can be reused as
       Matcher m = dependenciesToHash.matcher("");
       for (...) {
           m.reset(...).find() ...
       }
       btw, what's the spec of the "mach" here? a "match()" or a "find()"? just check.

-sherman