Case converters, nested menu, zipped package

• New command: Convert PascalCase <-> Dash (#50).
• The right-click menu is grouped into submenus: Whitespace, Case, Quotes, Encode / Decode, Color, Hash, Date and Time, Password, Network, JSON and PHP. The Hash submenu now also lists SHA224, SHA256, SHA384 and SHA512. Command names are unchanged, so key bindings keep working (#26).
• The case converters convert separated identifiers whatever their first letter: MAX_VALUE becomes maxValue or MaxValue, Foo_Bar becomes FooBar under PascalCase (previously foo__bar), and _private_name becomes _privateName, keeping leading separators. Selections that are not a single identifier, and capitalized text with an inner capital or only a trailing separator, behave as before (#32).
• The package installs as a zipped .sublime-package. Package Control moves existing installs over on upgrade and keeps a backup of the old folder (#35).