split avian::system::crash into its own file
add initial cmake script (only builds parts of the code)
add partial cmake build to ci.sh
add /cmake-build to gitignore
fix unused variable warning when building with cmake
Merge pull request #293 from joshuawarner32/cmake-initial

Add initial cmake build system
use c++11 enhanced-for and auto in type-generator
use c++11 variadic templates in Compiler::call
use enum class in ir
reformat
update README with new build requirements (gcc 4.6, MSVC 11)