Add govc-executable-name customization option

[tzz]

@dougm I hope this is useful. I needed it because my gopath is (intentionally) not part of my exec-path.

[vmwclabot]

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[dougm]

@tzz looks good, happy to add this. Wondering though, should we name this variable govc-command as that seems to be the convention (diff-command, grep-command, etc). We could also rename the existing govc-command function to govc-format to avoid any confusion.

[tzz]

That's exactly why I avoided govc-command ha ha. I did as you suggested, renaming the function govc-command to govc-format-command and creating the new defcustom. Change force-pushed.

[dougm]

thanks @tzz !

[vmwclabot]

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