Bug 912996: Fix whitespaces, r=qdot

--HG--
extra : rebase_source : 1494c72c57e9e47dd7e082ef39bc264d348b6224
Bug 912996: Remove memcpy when reading from Unix socket, r=qdot

We used to allocate memory on the stack when reading from a file
descriptor and copied the result into an instance of UnixSocketRawData.

This patch

 - cleans up the interface of UnixSocketRawData,
 - removes the large stack allocation (64KiB), and
 - removes the unnecessary memcpy.

Other memcpys for sending data have been moved into the constructor
of UnixSocketRawData.

--HG--
extra : rebase_source : 46ed1c73481732c3f3350bf0bedb56d376c24e98