NaCl docs: update version information

We'll be moving PNaCl's LLVM version to 3.4 soon, this change therefore removes '3.3' where it doesn't make sense to keep it, and adds it where it does.

R= binji@chromium.org, sbc@chromium.org, mseaborn@chromium.org
TEST=none
BUG= https://code.google.com/p/nativeclient/issues/detail?id=3757
NOTRY=true
(documentation only change)

Review URL: https://codereview.chromium.org/181573005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254873 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254873
Add widevine test directory to gitignore.

NOTRY=true

Review URL: https://codereview.chromium.org/187063002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254874 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254874