Including config.h is necessary to get e.g. the _GNU_SOURCE define and
any other definitions that autoconf declares. Hence, config.h needs to
be included as the first header in each file.
This is done either via:
1. Including "common.h" (i3bar)
2. Including "libi3.h"
3. Including "all.h" (i3)
4. Including <config.h> directly
Also remove now-unused I3__FILE__, add copyright/license statement
where missing and switch include/all.h to #pragma once.
This has multiple effects:
1) The i3 codebase is now consistently formatted. clang-format uncovered
plenty of places where inconsistent code made it into our code base.
2) When writing code, you don’t need to think or worry about our coding
style. Write it in yours, then run clang-format-3.5
3) When submitting patches, we don’t need to argue about coding style.
The basic idea is that we don’t want to care about _how_ we write the
code, but _what_ it does :). The coding style that we use is defined in
the .clang-format config file and is based on the google style, but
adapted in such a way that the number of modifications to the i3 code
base is minimal.
This removes code duplication, which will be useful for a subsequent
commit.
Furthermore, we now don’t open X11 connections unnecessarily in some
corner cases.
Orestis Floros