Partially refactored standard LaTeX options

Added hack for LaTeX VS Code extension

Added -synctex=1 to default LaTeX options

Changed all PlantUML rules to use -pipe ...

This seems to work more consistently with include files.
It also removes the need to rename LaTeX output files.

Whoops, missed the local configuration input file.

Added javac to configuration.

• Added PHP checks (closes #9).

• Moved commonly-used LaTeX flags into central infrastructure.

• Set up global, self-deleting temporary directory to use in situations where tools can’t be pipelined together (closes #5). ...

• Added mktemp command to configuration to support the above.

• Added some missing variables to the debug target.

• Fixed wonky variable in debug target.

• Reverted SVG to PDF conversions back to Inkscape, as it seems to do a better job of fonts than rsvg-convert, and the eariler performance issues appears to have been fixed.

• Redesigned how lecture file base names are constructed, to make it easier to include lecture numbers in the output file names. ...

• Added support for new DOC_NUM (replaces CHAPTER) and DOC_TYPE variables.
• Added missing defaults for various LaTeX options.
• Added support for new LATEX_FLAGS variable.

• Corrected --jobname to -jobname for LaTeX commands (although it worked anyway).

• Added a pdfcrop to the end of PlantUML → SVG pipeline, as different converters don’t always crop the output.

• Added PlantUML suffixes to standard list.

• Added COMBI_IMAGES and COMBI_FILES to debug output.

• Added PlantUML source files.

• Simplified commands to generate faded images, as the old version using composite stopped working for no readily apparent reason.

• Added *.vrb and _minted* to TIDY_FILES.

• Changed tidy and clean rules to use rm -rf so that we can include temporary directories.

• Added standard variables PAPER_INCLUDE_PATH and LATEX_INIT_FILE and rewrote all LaTeX-generating XSLT calls to use these. ...

• Revised passing of XSLT parameters to remove arbitrary limit on number of parameters.
• Synced up debug variables across different make include files.
• Fixed some raw calls to various commands.

• Added first cut at PlantUML rules.

• Added PlantUML to local configuration.

• Switched to rsvg-convert from Inkscape, as Inkscape has become horribly slow (too many fonts, perhaps?). rsvg-convert comes with librsvg.

• Added tr to miscellaneous required utilities.

• Added ability to install questions and answers independently.

• Added NOSYNC variable to support installation without sitecopy synchronisation.

• Removed unnecessary white space.

• Ensured that all notes targets are dependent on figures (if present).