Get default register from clipboard=unnamed setting
Coding style
VIM-476 Added default register reset on 'clipboard' change

Added a test for :set clipboard=unnamed.
Merge branch 'clipboard-unnamed'

Conflicts:
	src/com/maddyhome/idea/vim/option/Options.java
	test/org/jetbrains/plugins/ideavim/action/CopyActionTest.java
Added 'clipboard' to the list of :set commands
Added Thomas B Homburg to the list of contributors