build/log: Silence pdflatex output except on error

Issue #49.
build/log: Shave printed commands

Issue #49.
build/tools: Shave printed commands

Issue #49.
build/www: Shave printed commands

Issue #49.
build/www/css: Shave printed commands

Issue #49.
build/www/fonts: Shave printed commands

Issue #49.
build/www/img: Shave printed commands

Issue #49.
build/www/js: Shave printed commands

Issue #49.