Entity decoding, safer passwords, error reporting

• Generated passwords now come from a cryptographically secure generator. Characters can repeat, and lengths longer than the alphabet work.
• Convert HTML Entities to Chars decodes numeric references (Ш, Ш) and all HTML5 named references, including ' (#42, #47). Only references ending in ; are decoded.
• The camelCase, dash and PascalCase converters no longer raise an error when the selection does not fit the conversion (#41).
• Convert From Base64 reports invalid input in the status bar instead of failing silently (#52).
• Insert External IP uses https://api.ipify.org, reports network errors in the status bar, and inserts the address at every cursor (#36).