Syntax: attributes can start only in the beginning of lines

This is a workaround for the problem that previously that script thought that
the "- f()" part in the following line was a module attribute:

    [ A || A <- f() ]

Now the following code will not be highlighted well, but it is more rare than
list comprehensions:

    -attr1(). -attr2().
Rename repository to vim-erlang-runtime