imapc: Fix sending initial FETCH after reconnection SELECTs mailbox Move sending the FETCH when the SELECT returns tagged OK reply instead of delaying it until mailbox is next synced. Most importantly this allows sending the FETCH before any retried commands that are also sent after SELECT receives tagged reply.

imapc: Try to merge STOREs together as much as possible when syncing

global: unsigned int:1 -> bool:1 perl -i -pe 's/unsigned int ([^,:;]+):1;/bool $1:1;/' **/*.[ch]

Removed all the "enum foo;" declarations. They didn't seem to be very standard. Old gcc versions warn about them and C++ code doesn't like them.

imapc: Support retrying some IMAP commands if we get disconnected.

imapc: Initial support for local index files.

imapc: Many fixes related to syncing and error handling.

imapc: Added support for changing flags and expunging.

Added initial implementation of "imapc" storage. It can be used to create a "smart IMAP proxy" where Dovecot uses remote IMAP server as a mail storage. This is a very rough early implementation. Performance isn't good, many required features are missing, error handling is lacking and code needs de-uglification. Still, it should be enough for selecting INBOX and accessing mails in it.