make test/assert.rb cruby compatible
add test/bintest.rb
add conf.enable_bintest and run_bintest
add regression for #1564
add regression for #1572
add regression for #1563
enable bintest for travis CI
add a comment for enable_bintest in build_config.rb
Fix Kernel#global_variables for $1-$9
Merge pull request #1692 from Paxa/Kernel_global_variables

Fix Kernel#global_variables for $1-$9
resolve conflict in travis_config.rb