It is now possible to read values at once.

for (auto [name, value] : statement.tupleValues<String, int>(1000, "foo", 20))
   ....

Change-Id: I3d4bc5218810b4620e1df625126aa490f30bbc71
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

Using values instead of pointers makes the handling much easier. We can
remove ColumnDefinition too, and use SqliteColumn instead.

Change-Id: I224db9cc569c4dfb6e2746179b02096904bfbccb
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

We only will need the utf8 optimized SmallString for the indexer database.
So we remove all other string bindings, QByteArray and QVariant.

Change-Id: I4a77901a80b26bf292fc85df535c2ccf3a8ab52f
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

We don't need the threading anymore, so we removed it. The indexer
will be run in its thread anyway, so an extra thread makes the code
only more complicated. And we added namespaces.

Change-Id: Ibcba306324763285cf653c28bb08122345e5f8da
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

* Update remaining files in src

Change-Id: I1896f17fcf34f71c3310c87899fb5171b8e4afb1
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

This is a partial result of wip/clang-oop. More will follow.

This allows us to invoke the completion out of the Qt Creator process
and thus safes us as against libclang crashes.

At this point only the completion use case is supported.

Some notes on the individual components:

 src/libs/codemodelbackendipc
  * library encapsulating the inter process communication handling
  * used by the backend application and in a follow-up change by the
    creator integration

 src/libs/3rdparty/sqlite
  * version 3.8.10.2
  * dependency of codemodelbackendipc, will be used to storage indexing
    data, among others

 src/tools/codemodelbackend
  * the backend application

 tests/unit:
  * unit tests

Change-Id: I91a48e27467581a22fb760a18d8eb926008fea60
Reviewed-by: Alessandro Portale <alessandro.portale@theqtcompany.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>
Reviewed-by: Marco Bubke <marco.bubke@theqtcompany.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>