Merge pull request #21 from linquize/extern-c-dllexport

Add cangjiecommon.h to put commonly used stuff into it
Fix distcheck

I renamed these files a while ago, but didn't update the Makefile.am...
Fix distcheck

The new cangjiecommon header needs to be added to the Makefile.am
ci: Run distcheck every time

This should prevent us from breaking it in the future.
Add distcheck output to ignore list
Merge pull request #24 from linquize/distcheck

Add distcheck output to ignore list
Add .editorconfig

This helps developers maintain consistent coding styles by defining .editoconfig file.
See http://editorconfig.org/ for the file format.
Merge pull request #25 from linquize/editorconfig

Add .editorconfig
Merge pull request #23 from Cangjians/distcheck

Fix distcheck, and try to prevent future breakages
Merge remote-tracking branch 'remotes/linquize/master' into mingw