[fontloader] sync with Context as of 2014-03-22
[tool] add dummies for --bisect
[db,tool] add bisection initialization routines
[tool] add stop directive to bisect mode
[tool] reimplement bisect status directive
[db,tool,main] implement run directive for bisection mode
[tool] implement good/bad directives for bisection mode
[db,tool] implement termination of bisect session
[db,tool] display list of remaining files if less than ten
[db,tool] reconcile --bisect with --max-fonts