Update git submodules

Update git submodules

* Update docs/submodules/vid.git from branch 'master'
  to 779c51de46cf55648036361bb33e0470b28756ca
  - Run npm install as a frontend-maven-plugin goal

    Without this, "prebuild" step is using local npm, instead of
    frontend-maven-plugin one:

    npm ERR! Linux 4.4.0-134-generic
    npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install"
    npm ERR! node v4.2.6
    npm ERR! npm  v3.5.2

    Issue-ID: VID-391

    Change-Id: Ic9cd94898faaaf109b02d23640e652bd7e541753
    Signed-off-by: Ittay Stern <ittay.stern@att.com>