Usage:
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build_main.sh [options] build_into "destination_dir"
  Perform the page build. Write output to destination_dir. The source
  directory is determined from the build scripts own location.

build_main.sh [options] build_xmlstream "file.xhtml"
  Compile an xml stream from the specified file, additional sources will be
  determined and included automatically. The stream is suitable for being
  passed into xsltproc.

build_main.sh [options] process_file "file.xhtml" [processor.xsl]
  Generate output from an xhtml file as if it would be processed during the
  build. Output is written to STDOUT and can be redirected as desired.
  If a xslt file is not given, it will be chosen automatically.

build_main.sh [options] tree_maker [input_dir] "destination_dir"
  Generate a set of make rules to build the website contained in input_dir.
  destination_dir should be the www root of a web server.
  If input_dir is omitted, it will be the source directory determined from
  the build scripts location.
  Note: if destination_dir is set via previous options, and only one parameter
  is given, then this parameter will be interpreted as input_dir

OPTIONS
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--source "source_dir"
  Force a specific source directory. If not explicitly given source_dir is
  determined from the build scripts own location. 
  Paths given in .sources files are interpreted as relative to source_dir
  making this option useful when building a webpage outside of the build
  scripts "regular" tree.

--destination "destination_dir"
  The directory into which the website will be built. This option can be used
  in conjunction with the tree_maker and build_into commands. It will override
  the destination_dir option given after those commands and is therefore
  redundant. The option exists to provide backward compatibility to the 2002
  build script.

--statusdir "status_dir"
  A directory to which messages are written. If no status_dir is provided
  information will be written to stdout. The directory will also be used
  to store some temporary files, which would otherwise be set up in the
  system wide temp directory.

--build-env "selection"
  Indicate the current build environment. "selection" can be one of:
  * "fsfe.org": building https://fsfe.org on the production server
  * "test.fsfe.org": building https://test.fsfe.org on the production server
  * "development" (default): local development build
  In a local development build, code to dynamically compile the less files into
  CSS will be included in the HTML output, while in the other environments, the
  precompiles fsfe.min.css (or valentine.min.css) will be referenced from the
  generated web pages.