mode name

[Tak Ota]

Many modes have a name (the third argument to define-derived-mode)
consisting of more than one words.  Some use '-' to concatenate each
word in the name string while many leave a space between words.  The
latter is annoying on the mode line when it is listed together with
other mode names since each mode name is separated by a space too.
Can we change all those spaces in mode name to '-' so that each mode
name stands out from each other?

-Tak