Add two new options to our documentation infrastructure.
TWO_SIDE - If defined, two sided output will be created. This means that new chapters will only start on odd numbered (aka right side, aka recto) pages and the headers and footers will be aligned appropriately for double sided paper. Blank pages may be added as needed. BOOK_OUTPUT - If defined, this will set all of the other print-output options that can significantly increase the build time, but make for much nicer looking output.
To implement the two sided output, we need to override a TeX variable
to control the behavior of the JadeTeX macro package. So this also
introduces a TEXCMDS variable that can be set with additional TeX
commands that should be run before processing the input TeX document.
In the TWO_SIDE case, we simply set it to \def\PageTwoSide{1}