update some libraries

Try and clean up more in powerpoint

Perform a check that there are printers installed. If there are not, …

…then don't attempt to convert as office will complain.

Also checks the /printer and /fallback_printer names are installed

Merge branch 'master' of https://github.com/cognidox/OfficeToPDF

cognidox#22 - Adds the /powerpoint_output switch

More copyright changes

Alter how we close Word

catch potential issues when modifying the column widths (cognidox#14)

Adds a /working_dir switch so we chose where to open files from.

Changes how Word and PowerPoint are fired up to see if we can trap COM issues

Release 1.8