Style and positioning fixes to form elements in the Publish box:

- Make select element text #555 to match others
- Make Cancel links vertically align with buttons
- Make sure the spacing between buttons and cancel links is always consistent
- Override active button styles for responsive states so button size doesn't change when active
- Reduce font size of date select element to match date text inputs

Fixes #26082, props aubreypwd.


Built from https://develop.svn.wordpress.org/trunk@26247


git-svn-id: http://core.svn.wordpress.org/trunk@26153 1a063a9b-81f0-0310-95a4-ce76da25c4cd