Improved FileManager.typeset_latex_file(). NOTE.

FileManager.typset_latex_file() now calls pdflatex TWICE on the path controlled
by FileManager.

NOTE: this is important because some packages like tikz (and also bibtex)
require LaTeX to be called in two passes.

RESULT: this means that the rectangular bounding box included on our front
cover template now renders correctly.

Note, too, that after calling pdflatex twice, FileManager then removes the
intermediate artifacts produced by pdflatex. This helps keep the filesystem
keep. But note that removing the intermediate artifacts *in between the two
calls to pdflatex* renders the effects of the two passes ineffective.