thoughtbot/bourbon — pull request #427 by whmii (2014-05-16 15:27:03+00:00)
Title: Add vertical align baseline to button mixin

Currently vertical-align for buttons is not specified. This can result in strange alignment issues (see attached). `vertical-align: baseline` results in a more constant appearance.
![button-valign](https://cloud.githubusercontent.com/assets/2489247/2998715/1d0b9c74-dd0e-11e3-8c98-73bbecc60344.png)