v0.3

Changes:

• Add group chat support and messages:
  • list chats on account: account <id> chat list
  • join a chat on account: account <id> chat join <chat>
  • part a chat on account: account <id> chat part <chat>
  • send a message to a chat on account: account <id> chat send <chat> <message>
  • list users of a chat on account: account <id> chat users <chat>
• Cleanups, fixes, and improvements