angular-websocket: new package

angular-websocket: new package

Signed-off-by: Bimal Jacob <bimal.jacob@rockwellcollins.com>
Signed-off-by: Matt Weber <matthew.weber@rockwellcollins.com>
[Thomas:
 - Move to a submenu "External AngularJS plugins", much like we have an
   "External JQuery plugins" menu. Therefore, remove the "select
   BR2_PACKAGE_ANGULARJS" from the package, since
   angular-websocket/Config.in is now included only if
   BR2_PACKAGE_ANGULARJS is defined.
 - Add hash file.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>