Improved usage of commands.

Added function "(c *CmdClause) Name() string".
Replace "(*CmdClause").Name()" with "(*CmdClause).FullCommand()".

"(*CmdClause").Name()" is removed.
"(*CmdClause).FullCommand()" is renamed from "(*CmdClause).fullCommand()".
Merge pull request #8 from probkiizokna/master

Improved usage of commands.