Add a contribution information file
Emphasis commands
re-formulate some sentences
Merge pull request #474 from monaka/pr-generic-sh-elf-support

Generic sh-elf target support.
Merge pull request #475 from bovi/contributing

More Contributing Documentation
Built generator for an variable amount of gems
remove second gem
Some additional changes to compile properly
Merge remote-tracking branch 'upstream/master' into mrbgems
Ignore generated files
Modify information messages
add hello world test program
Add default makefile for Gems
Integrate tests into mrbgems
Remove TODO. This point is finished
OP_CALL for cfunc must restore callinfo; close #476
Merge branch 'master' of github.com:mruby/mruby
Merge remote-tracking branch 'upstream/master' into mrbgems
Optimize Makefile
should adjust pc after OP_CALL