Imap-tools

* Add deprecated Q to default import, *forgot =)

* Added 14 new custom lib exceptions (errors.py): MailboxCopyError, MailboxDeleteError, MailboxExpungeError, MailboxFetchError, MailboxFlagError, MailboxFolderCreateError, MailboxFolderDeleteError, MailboxFolderRenameError, MailboxFolderSelectError, MailboxFolderStatusError, MailboxFolderStatusValueError, MailboxLoginError, MailboxLogoutError, MailboxSearchError
* UnexpectedCommandStatusError now not used directly.
* Added folder.MailBoxFolderStatusOptions class instead MailBoxFolderManager.folder_status_options
* utils.MessageFlags -> message.MailMessageFlags
* query.py: ValueError replaced to TypeError in many places
* utils.short_month_names renamed to utils.SHORT_MONTH_NAMES
* utils.cleaned_uid_set - parsing optimized, raise TypeError instead ValueError, not ignore empty uid from generator
* utils.check_command_status - new logic
* BaseMailBox.fetch headers_only arg is disabled until fix

* Query builder: removed Q alias for AND
* Query builder: added new aliases: A for AND, O for OR, N for NOT

* Added X-GM-LABELS support to query builder (gmail_label)

* added BaseMailBox.fetch headers_only argument - get only email headers
* BaseMailBox.attachments now can returns nameless attachments (inline/forwarded)
* MailBoxFolderManager.list result changed: item['flags'] now are tuple(str)

* mailbox.MailBox splitted to: BaseMailBox, MailBox, MailBoxUnencrypted
* MailBox ssl argument deleted
* mailbox.MessageFlags class moved to utils.MessageFlags
* Add PySocks proxy examples