update: bug fixes, windows desktop app works now.
update: bug fixes, windows desktop app works now.

- on desktop app window close, the main desktop process still kept
running in background. was missing app.quit() at right place. fixed it
in this commit.
- in windows spawn() was not executing iguana.exe file, and was not
exiting when app quits. updated to use exec() for both starting and
killing iguana.exe process with command `taskkill`. windows desktop app
works now.

pbca26/iguana,SuperNETorg/iguana,SuperNETorg/iguana,pbca26/iguana,pbca26/iguana,SuperNETorg/iguana