Overview of changes:

 *  Fixed non-existent cache on first run breaking locking

Overview of changes:

 *  Added missing make build dependency

Overview of changes:

 *  Improved logic of CA certificate storage

    Now imapdomo will only default to local 'certificates' file if it
    exists -- if it does not exist it will leave -t option for
    imapfilter alone, meaning that the system storage will be used.

    Both behaviors can be forced on command line by -t or -T arguments.

 *  Added few missing option description in usage message

Overview of changes:

 *  Set default queue size 512 for get_queue()

 *  Fixed traceback from head() on missing sequence argument

Overview of changes:

 *  Added head() method to get first N messages in sequence

 *  Updated URLs after migrating to GitLab.com

 *  Enabled Gladness pipeline

 *  Minor packaging cleanup

Overview of changes:

 *  Fixed messed up rule insertion method

Overview of changes:

 *  Fixed syntax error in previous release

Overview of changes:

 *  We won't prevent handlers from loading other modules

Overview of changes:

 *  Added experimental ruleset manager

    Instead of manipulating queue over and over, handler can now
    start a ruleset tied to a queue loader and add rules as functions
    that always operate on freshly loaded queue.  Once queue stops
    yielding no more rules are executed, saving unnecessary round trips
    with server.

    To make this work with least possible amount of typing to use,
    this module is stateful operation, but with some basic care it
    should  be safe and overall the ruleset approach should make it
    easier to prevent conflicts such as when later, more inclusive rule
    overrides former.

Overview of changes:

 *  Updated MKit to v0.0.40

 *  Switched to newer branch naming scheme

Overview of changes:

 *  Revamped packaging and handler API for Lua-correctness

    Most of imapdomo now behaves more like proper Lua code and part of
    this also rubs off to user, OTOH it only relates to one-time changes
    it's balanced by some extra configuration freedoms.

 *  Added support for hooks

    Handlers can now call dedicated external scripts prepared by user
    in advance, under `.imapdomo/config/hooks`.  The API is not fully
    fleshed, though.

 *  Enabled lock-related debugging

Several changes regarding packaging, namespacing and handler API:

 *  Utility function module is now called 'imapdomo', not 'common'.

 *  The module behaves as one, instead of being just a global-modifying
    include.

 *  Lots of cleanups as advised by luacheck (local declarations,
    removal of unused variables...)

 *  Handlers now have to access utility API via `require` and provide
    accout configuration in new file mailboxes.lua, which has to return
    table.  Accessing mailboxes is via utility function.  (This sounds
    complicated but actually is not.  Believe me! :))

Overview of changes:

 *  Fixed some grep calls to avoid ambiguities

 *  Update MKit to latest version

 *  Added few notes about performance and lock disabing

 *  Updated URLs after move from github

Where regular expression is read from a variable and -e argument is not
provided, the resulting call may end up being interpreted as grep
argument.

See also:

    https://github.com/koalaman/shellcheck/issues/1342

Overview of changes:

 *  Added locking mechanism

    We have to assume that filtering can take long, so if cron is used
    to launch imapdomo and gap is too small, imapdomo instances could
    run over each other, increasing the load even more.

    Now imapdomo drops a lockfile by default, and silently gives up if
    lockfile exists.  This can be disabled by command line switch.

 *  Removed dead code

Action won't start if one is already running.  This should prevent
overlapping actions.

It's possible to turn off locking to allow running imapdomo as service,
ie. locking will be taken care of by init system.

Dead since 919fa12, ie. v0.0.4

Overview of changes:

 *  Codebase maintenance

 *  Small improvements

 *  Added proper license

For code readability and maintenance

Use `%global` definition for Shellfu requires and cluster fields
according to relevancy (source vs. build).