Moved doveadm zlib commands from zlib plugin to doveadm directly. Previously it was a plugin, because the istream-zlib existed only in zlib plugin. Now there's a lib-compression that implements it.

Moved zlib/bzlib code to lib-compression library.

Use -Wl,--as-needed -Wl,--no-undefined GNU ld flags for non-plugins.

Added doveadm zlibconnect command for testing IMAP COMPRESS.

doveadm dump: Added imapzlib type to uncompress IMAP's COMPRESS DEFLATE I/O traffic.

zlib: Avoid using hardcoded storage name strings.

zlib plugin: Added support for compressing Maildir mails while saving. --HG-- branch : HEAD

Get rid of imap/, pop3/, lda/ and sql/ module subdirs. It's all in lib/dovecot/ now. --HG-- branch : HEAD

zlib: Install the plugin also to pop3 directory. --HG-- branch : HEAD

zlib plugin supports now bzip2 also. --HG-- branch : HEAD

Changed the plugin filename numbering (ie. the ordering in which the plugins are loaded). This doesn't change anything for current plugins, but future plugins will need this change so they can get themselves loaded between specific plugins. --HG-- branch : HEAD

Link with zlib. --HG-- branch : HEAD

Added zlib plugin --HG-- branch : HEAD