Currently, a lot of our build variables that are defined at
configuration time, are spread out across the code base, often declared
as `extern` which can break when moving around sections of the code
across files.
This commit introduces a "Config" namespace which basically maps to the
definitions in `config.h`, but allows us to properly access them too
from the Vala source code.
By doing so, it helps us to more explicitly see where we rely on a
build variable from this file (which should be obvious from the `Config'
namespace).
To make it ourselves a bit easier in Meson too, we can declare an
internal dependency, which helps ensure that we pull in the dependency
where needed.
Engine mocks don't need to be in the `Geary` namespace, and including
them there makes it difficult to use them in client tests, so put them
all in their own name-space and corresponding directory.
Move args from open_async to ctor and use these to determine and store
DB file and attachment paths as properties. This allows constructing
the DB instance up front and markig it as non-nullable, simplifies
calling patterns and hence allows removing one use of the deprecated
Engine singleton, and by moving in the local data deletion
implementation from ImapEngine.GenericAccount, also allows removing a
static helper method.
Add a ContactHarvester arg to ImapDB.Folder.create_or_merge_email and
call it on the resulting email. Add and update a new harvester
property to MinimalFolder and pass that in as needed.
Updating the unread count after opening a folder and finding email that
has an unexpected unread status messes up the count obtained from the
server, which has already taken these messages into account.
Here, both the main normalisation process and the email flag updater are
prevented from adjusting the unread count for a folder when they
encounter email that are new and unread, or have an unread status
different from what was last seen by the engine.
See #213
