Fixed LaTeX conversion on Windows

I fixed conversion to latex on Windows platforms so that filenames are entered into LaTeX correctly (using forward slash, not backslash as os.path.join provides.).  I believe this change should not affect Linux (b/c "\" will not appear in the path).  I Also updated the pandoc call to remove word wrapping.  The word wrapping resulted in double-new-lines in windows .tex files, causing new paragraphs each time a line wrapped.