Quote filenames containing whitespace in argument to SyncTeX if called via 'exec'.

[xax]

See issue #91.

This patch is not thoroughly tested, as I do not have the opportunities to do that right now (– that being the reason I opened an issue instead of posting a pull request in the first place).

And you can think of other approaches to tackle the issue, too: Unconditionally quote, quote entire clickspec argument, quote upon other characters as well…

[l0calh05t]

It would be better to just shell escape clickspec in its entirety. That way only the exec version would be affected by the code changes. node-shell-escape could be used for this purpose (although it might not be suitable for windows.. linux and windows escaping are different).

[izuzak]

Thanks for opening a pull request. 🍰 I cleaned this up a bit and merged.