Update gitignore for the name-change of the executable

Update gitignore for the name-change of the executable

It's not called 'parse' any more.  And I think I should rename 'divelog'
too to something more unique.  Right now the working name for the
project is 'diveclog' (kind of like 'jdivelog') , but I'm not convinced
that the "C implementation" part is really important enough to make a
point of long-term.

"subsurface"? I don't know.  Maybe I should follow the "name all
projects after myself" mantra.  "divenut"?

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>