Fix Makefile's attempt to infer value for SDL_MODE.

The `ifeq` check does not work without surrounding double-quotes if
SDL_MODE is unset.
remove outdated Vec imports
Allow deriving(Eq) for individual cases using raw pointers.
Switch to new inner attribute syntax.

Inner attributes now written `#![inner(attr)]` rather than `#[inner(attr)];`
Merge pull request #62 from pnkfelix/mk-fix-sdl-check

Fix Makefile's attempt to infer value for SDL_MODE.
Merge pull request #63 from pnkfelix/misc-updates-for-newer-rustc

Misc updates for newer rustc
`append_one` is now a method of `Vec`

(Also added a type hint for the compiler to deduce what `flags_out`
contains at the time `append_one` is called.)
(Changed all structs to public vis. by default)
Merge branch 'exp/fix-visibility' into exp/fix-append-one
README: add reference link to rust-sdl2_ttf
Merge pull request #67 from andelf/add-ref-link-to-sdl2_ttf

README: add reference link to rust-sdl2_ttf
Merge pull request #65 from drbawb/exp/fix-append-one

Use new `Vec#append_one()` method
update for newer rust: use libc crate instead of std::libc
Add RWops struct implementation
fix #38, use close_on_drop option in RWops
Merge pull request #70 from andelf/add-rwops-struct

Implement SDL_RWops in Rust as sdl2::rwops::RWops
make RWops compatible to i686 platform; also add more patterns to .gitignore.
Merge pull request #1 from lifthrasiir/i686-compat-rwops

make RWops compatible to i686 platform; also add more patterns to .gitig...
README: Add reference link to rust-sdl2_mixer
Merge pull request #72 from lifthrasiir/i686-compat-rwops

Make `RWops` compatible to i686 platform; Also add more patterns to .gitignore.