Escape filename for pdflatex in nbconvert

[astrofrog]

This is a simple change, but it's needed otherwise filenames with spaces cause issues:

$ ipython3 nbconvert 12.\ Files\ and\ strings\ \(advanced\).ipynb --to latex --post PDF
[NbConvertApp] Using existing profile dir: '/Users/tom/.ipython/profile_default'
[NbConvertApp] Converting notebook 12. Files and strings (advanced).ipynb to latex
[NbConvertApp] Support files will be in 12. Files and strings (advanced)_files/
[NbConvertApp] Loaded template latex_article.tplx
[NbConvertApp] Writing 30139 bytes to ./12. Files and strings (advanced).tex
[NbConvertApp] Building PDF: `pdflatex ./12. Files and strings (advanced).tex`
/bin/sh: -c: line 0: syntax error near unexpected token `('
/bin/sh: -c: line 0: `pdflatex ./12. Files and strings (advanced).tex'
/bin/sh: -c: line 0: syntax error near unexpected token `('
/bin/sh: -c: line 0: `pdflatex ./12. Files and strings (advanced).tex'
/bin/sh: -c: line 0: syntax error near unexpected token `('
/bin/sh: -c: line 0: `pdflatex ./12. Files and strings (advanced).tex'

[minrk]

We really shouldn't ever be building subcommands as a single string when we don't have to. Do you want to change the code so that the configurable is actually a list? Something like:

    command = List(["pdflatex", "{filename}"], config=True,...)
    ...
    command = [ c.format(filename=input) for c in self.command ]

[astrofrog]

@minrk - no problem, I'll see what I can do

[astrofrog]

@minrk - I implement it the way you suggest, which I agree is cleaner. Would you prefer for me to rebase and squash the commits?

[minrk]

maybe rename 'compiler' to 'command'

[minrk]

No need to rebase. Rename 'compiler' to perhaps more accurate 'command', and it should be ready to go.

[minrk]

Thanks!