[qtcontacts-sqlite] Improve DLG plugin interface. Contributes to JB#44742

See merge request !17

[qtcontacts-sqlite] Allow empty sub-type for urls and anniversaries. Contributes to JB#44713

See merge request !18

Make it possible to specify a url/anniversary without a sub-type.

This commit improves the display label group plugin interface by
allowing plugins to report whether the specified locale is a
preferred locale for them, rather than merely valid, as some
plugins may work in multiple locales but should be preferentially
used (e.g. to determine the default display label groups) for
a subset of those locales.

For example, a pinyin grouping plugin might be valid in all locales
but preferred in locales which use Simplified Han writing script.

The database now populates the "default" supported display label
groups from the highest priority preferred plugin rather than
the highest priority valid plugin (falling back to highest priority
valid plugin if no preferred plugins exist for the current locale).

[qtcontacts-sqlite] Cleanups. Contributes to JB#38781

See merge request !16

Fix style, remove dead code etc.

And fix build in CI

Jb44707 core apps

See merge request !15

If some other process is holding open a database connection, the
database may not have been correctly upgraded to the current
schema version.

Previously, this could result in new processes assuming that
the schema was upgraded, and attempting to perform queries which
fail due to the fact that the real database schema might be
old.

This commit ensures that we detect this case, and print an appropriate
warning so that the user can take the appropriate action
(e.g. kill the offending process, or reboot the device).

[qtcontacts-sqlite] Automatically extend known display label groups at runtime. Contributes to JB#44742

[qtcontacts-sqlite] Allow , and . as DTMF pause. Contributes to: JB#44709

See merge request !14

[qtcontacts-sqlite] Don't link against QtGui unnecessarily. Contributes to JB#36025

See merge request !12

[qtcontacts-sqlite] Workaround issue with QWaitCondition. Contributes to MER#1853

See merge request !11

[qtcontacts-sqlite] Mark method overrides

See merge request !10

[qtcontacts-sqlite] Run tests with "make check"

See merge request !9

If the database has been left dirty by some other test, this test will
fail. So, cleanup the DB before running this test.

QWaitCondition::wait() will immediately return false on 64bit
architectures if the timeout value is greater than MAX_INT.
https://bugreports.qt.io/browse/QTBUG-54625

Add the "override" keyword to virtual method implementations. This will
turn out to be helpful when upgrading to a new QtPim version: since
sometimes QtPim changes the signature of virtual methods, the override
keyword guarantees that we'll get an error when our methods stop being
called.

Add a "check" target, so that tests can be run uninstalled, with "make
check". In the .pro files, define the TARGET variable before including
the common.pri file, which needs this variable to define the command to
be executed.

In order for the tests to load the plugin, it needs to be moved into a
"contacts" subdirectory; do this with the DESTDIR variable.

[qtcontacts-sqlite-extensions] removed unused static function

See merge request !8

Remove usage of QtContacts private headers

See merge request !7

The maxModificationTimestamp() function is declared inside an unnamed
namespace, making it effectively a static function. It's also unused
since 6959456f (in 2014!), and it causes
a compilation warning in Ubuntu.

Use QCoreApplication to pass the engine from the plugin to the extension
code.

Some feature from C++11 is used (at least one "nullptr" was found in the
source code).

[Qt] QFlag won't take a ulong on an LP64 environment. Contributes JB#36790

QFlag has several constructors, and they all just convert to an int anyway.

See merge request !6