.ui file extension added for XML language

Qt uses .ui files to store qtdesinger ui in xml
Add extension support for Iced Coffeescript
The extension list is alphabetized
Update samples db
Don't emit the diff if samples db is out of date

There's a warning message emitted with instructions, a 2000 line diff
does nothing to help the user track down the issue.
Merge pull request #438 from richo/bugs/sample_db

Bugs/sample db
Merge pull request #373 from vincentwoo/patch-1

Add extension support for Iced Coffeescript
Remove XProc and XSLT from the group XML
Merge pull request #441 from rdeltour/xml-group

Remove XProc and XSLT from the group XML
Merge branch 'master' of github.com:github/linguist

Conflicts:
	lib/linguist/languages.yml
Order is fixed
Merge pull request #349 from tucnak/master

Support of Qt Designer .ui files
Render Ceylon as Ceylon since it is now in Pygments
Merge pull request #446 from github/ceylon-as-ceylon-not-textonly

Render Ceylon as Ceylon since it is now in Pygments