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
Merge pull request #23 from Cangjians/distcheck

Fix distcheck, and try to prevent future breakages