multiple syntax files use "hi link" instead of "hi def link"

Multiple syntax files contain "highlight" commands without the "default" argument. This means the syntax file overrides color schemes every time it is processed, which is usually whenever a buffer of the matching file type is read. While not a particularly serious bug, it is an irritating one.

I first noticed it soon after upgrading to precise in the $VIMRUNTIME/syntax/erlang.vim file. A search of the syntax directory revealed many more case of this.

I am willing to submit fixes for this.

-----
Description: Ubuntu 12.04.1 LTS
Release: 12.04

vim-runtime:
  Installed: 2:7.3.429-2ubuntu2.1
  Candidate: 2:7.3.429-2ubuntu2.1
  Version table:
 *** 2:7.3.429-2ubuntu2.1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     2:7.3.429-2ubuntu2 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages