re-implement RCWebColorPicker as colorpicker

This Cask dates from before the existence of the colorpicker artifact type.
- chg artifcact type to colorpicker
- remove caveats
- rename to match other colorpickers
add man page brew-cask.1
doubledash hygiene for external cmd: sudo, AND

also includes doubledash hygiene for any child commands following each sudo
doubledash hygiene for external cmd: mv
doubledash hygiene for external cmd: ln
doubledash hygiene for external cmd: ls
doubledash hygiene for external cmd: stat
doubledash hygiene for external cmd: rm
doubledash hygiene for external cmd: ditto
doubledash hygiene for external cmd: open
doubledash hygiene for external cmd: rmdir
doubledash hygiene for external cmd: launchctl
doubledash hygiene for external cmd: chmod
doubledash hygiene for external cmd: kextunload
doubledash hygiene for external cmd: file
add new method depends_on_formula to odumpcask
add HOMEBREW_TAP_FORMULA_REGEX constant in tests

because our code tries to use it when throwing exceptions
also move HOMEBREW_BREW_FILE from doctor_test.rb to test_helper.rb
add reboot caveats to soundflower
Merge pull request #2740 from rolandwalker/soundflower_caveats

add reboot caveats to soundflower
tiny nits on new Screen Saver artifact

whitespace, filenames, orthography to be consistent with
other artifacts. No functional change.