Revert "Context actionbar for the account screen."

We're not ready for this sort of living in the futre yet.

This reverts commit 0f51eb54.

Conflicts:
	res/drawable-hdpi/ic_action_settings_light.png
	res/drawable-ldpi/ic_action_settings_light.png
	res/drawable-mdpi/ic_action_settings_light.png
	res/drawable-xhdpi/ic_action_settings_light.png
	res/menu/accounts_context.xml
	res/values/strings.xml
	src/com/fsck/k9/activity/Accounts.java