Concatenated .gz files/streams

[Xueming Shen]

Martin,

Though there is different opinion that "it is not obvious that accepting 
multiple .gz files concatenated
together is actually an improvement" back to 2006:-)  it appears rfc1952 
clearly specifies "A gzip file
consists of a serious of "members"..." in its "File format" section[1], 
and more importantly:-) some of
my new colleagues are very interested to have this rfe addressed because 
there is real world product
actually still heavilly uses concatenated .gz files. So here is the 
webrev of a reasonable fix and the test
case. (The test case only run against the output from GZIPOutputStream, 
I did test on couple .gz files
from gzip, just don't want to introduce in gzip dependency into the test 
case)

http://cr.openjdk.java.net/~sherman/4691425/webrev/

-Sherman

[1] http://www.gzip.org/zlib/rfc-gzip.html#file-format