Update the Vim syntax prelude.
fixed markdown rendering a H1 in comment
test/run-make: some test cases lacked $(EXTRACFLAGS).

Signed-off-by: NODA, Kai <nodakai@gmail.com>
auto merge of #19125 : chris-morgan/rust/vim-prelude-2014-11-20, r=alexcrichton
auto merge of #19132 : sinistersnare/rust/patch-1, r=alexcrichton

Just used Githubs edit view, so I hope this works...
auto merge of #19133 : nodakai/rust/run-make-tests-missing-extracflags, r=alexcrichton

Missing `$(EXTRACFLAGS)` resutled in compile failures.