'Home' & 'End' translation difficult

'Home' & 'End' translation difficult

There are two 'Home' strings in command.c. One of them means button
name, and other means the action. Translators (like me) have only one
in pot-file and can not translate them right. Button name 'Home'
always does not need to be translated, but the action 'Home' must be.

I propose to rename action to something like 'Move cursor Home'. As
result we will have two strings to translate except one.

All of this concerned also 'End'.