#427 Implement buffer variable overrides for all linter options

ale_linters/cs/mcs.vim

@@ -1,7 +1,7 @@
 let g:ale_cs_mcs_options = get(g:, 'ale_cs_mcs_options', '')
 
 function! ale_linters#cs#mcs#GetCommand(buffer) abort
-    return 'mcs -unsafe --parse ' . g:ale_cs_mcs_options . ' %t'
+    return 'mcs -unsafe --parse ' . ale#Var(a:buffer, 'cs_mcs_options') . ' %t'
 endfunction
 
 function! ale_linters#cs#mcs#Handle(buffer, lines) abort