Fix Coverity reports of Uninitialized scalar variable with the vertex struct. Should vertex ever be converted to a class from a struct, these memsets as well as the pre-existing ones will need to be removed in favour of a proper constructor of the then vertex class.

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10732 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Coverity 1093783 Uninitialized scalar variable with opengl_light structure in gr_opengl_set_center_alpha()

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10733 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Coverity 1093788 Uninitialized scalar variable - no need for bitwise AND when value is so far unset

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10734 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Coverity 1093799 Uninitialized scalar variable -- initialise array contents to zero

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10735 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Coverity 1093638, 1093640 and 1093667: Out-of-bounds access in tcp_client.cpp

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10736 387891d4-d844-0410-90c0-e4c51a9137d3
Fix Coverity 1093663: Out-of-bounds access in multi_oo_pack_data()

git-svn-id: svn://svn.icculus.org/fs2open/trunk@10737 387891d4-d844-0410-90c0-e4c51a9137d3