PNaCl documentation: update FAQ

Many things were out of date, especially around PNaCl.

Sorry for the mass-spam of reviewers: I figure out FAQ should be awesome and should probably cover more than what it currently covers.

R= eliben@chromium.org, mackinlay@chromium.org, binji@chromium.org, sbc@chromium.org, dschuff@chromium.org, jvoung@chromium.org
BUG= https://code.google.com/p/nativeclient/issues/detail?id=3634
NOTRY=true

Review URL: https://codereview.chromium.org/24705002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226239 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226239
[NaCl SDK] Add example code for TCP listening socket.

This change adds a simple echo server to the socket
example, that is implemented using a TCP listening socket.

R=binji@chromium.org, noelallen@google.com

Review URL: https://codereview.chromium.org/24165009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226240 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226240