Fix a -Wformat bug exposed by compiling with Clang.
To preprocess C++11 code, you need `g++ -E -std=c++11`, not just
`g++ -E`. (The old code worked for GCC 6+ and Clang 6+ because they
changed the default mode from C++03 to C++14. But for GCC 5, we still
need `-std=c++11`. And regardless, it's a good idea.)
Add a "-mac" option to mymake, and cleanly factor out `set_mac`,
`set_linux`, and `set_win`. When you build mymake using
`make -f Makefile.simple mymake`, you get a mymake that knows what
platform it's on. This means you don't have to pass `mymake -mac`
on OSX, nor `mymake -win` on Windows.
The old code put `INCLUDE(___hyper-main.cpp)` into a C++ file that
would be preprocessed, which doesn't work because libSDL does
essentially `-Dmain=SDL_main`, which turns this into
`INCLUDE(___hyper-SDL_main.cpp)`, which gives us
a "file not found" error from mymake. The solution is to put
filenames into quotation marks, so that the string "main" never
appears as a token in the C++ file. (Alternatively, we could have
renamed "hyper-main.cpp" to "hypermain.cpp".)
Add several new "mymake" entries in the Travis build matrix,
and add the "mymake" builds' badge to the README.
For testing the emscripten build in TravisCI, it looks like some
arcane combination of node + Browserify + the wasmify plugin + maybe
some other stuff *might* work, but I have no real idea yet.
For grabbing the build artifacts from Travis, you can temporarily
insert lines into the .travis.yml such as
curl --upload-file ./hyper.html https://transfer.sh/hyper.html
curl --upload-file ./hyper.js https://transfer.sh/hyper.js
curl --upload-file ./hyper.wasm https://transfer.sh/hyper.wasm
However, "hyper.wasm" is about 2.8 megabytes in size, so this hack
definitely should never become part of the *master* `.travis.yml`.
