Moves all dependency building into App
bootstrap.php returns an App instance
The app loads config files as necessary
Moves logging to Monolog
Moves HTTP digest auth to packagist component
Rely on sys_get_temp_dir
Env hosts $_POST and allows defaults when reading
HTML helper uses the App and can handle less files
Source factory assumes strings are filenames
Fixes JsClosureCompilerTest::test6 (API now handles ES5 by default)
Exclude JsClosureCompilerTest due to API limitations
config.php can now return a Minify\Config object
Variables set in config.php are now moved to a `Minify\Config` object,
allowing better static analysis.
The `zlib.output_compression` set is moved into `Minify::serve`.
2.2 used empty string as a magical value meaning do not minify, but
in the refactoring `Minify::combineMinify` forgot to interpret this
value that way and instead inherited the default compressor for the type.
This eliminates `""` as a magical value, but for BC rewrites it to
`Minify::nullMinifier` in the sources.
Fixes#499
