Follow-Up of 7db3fa94a1 .
This was done by setting `CMAKE_C_INCLUDE_WHAT_YOU_USE` and
`CMAKE_CXX_INCLUDE_WHAT_YOU_USE` to (broken down into multiple lines here,
note, all below `FL/x.h` is not required for C):
```
include-what-you-use;
-Xiwyu;--mapping_file=/usr/share/include-what-you-use/qt5_11.imp;
-Xiwyu;--keep=*/xmmintrin.h;
-Xiwyu;--keep=*/lmmsconfig.h;
-Xiwyu;--keep=*/weak_libjack.h;
-Xiwyu;--keep=*/sys/*;
-Xiwyu;--keep=*/debug.h;
-Xiwyu;--keep=*/SDL/*;
-Xiwyu;--keep=*/alsa/*;
-Xiwyu;--keep=*/FL/x.h;
-Xiwyu;--keep=*/MidiApple.h;
-Xiwyu;--keep=*/MidiWinMM.h;
-Xiwyu;--keep=*/AudioSoundIo.h;
-Xiwyu;--keep=*/OpulenZ/adplug/*;
-Xiwyu;--keep=QPainterPath;
-Xiwyu;--keep=QtTest
```
FAQ:
* Q: Does this speed-up a completely fresh compile?
* A: No, I measured it.
* Q: Does it speed up anything else?
* A: Yes. If you change one header, it can reduce the number of CPP files
that your compiler needs to recompile, or your IDE has to re-scan.
* Q: What other reasons are for this PR?
* A: It's idiomatic to only include headers if you need them. Also, it will
reduce output for those who want to use IWYU for new PRs.
Background:
This is just a remainder PR of what I planned. My original idea was to setup
a CI which warns you of useless includes (but not of all issues that IWYU
complains about). However, I could not see that this was favored on Discord.
A full IWYU CI also has the problem that it (possibly??) needs to compile
with `make -j 1`, which would make CI really slow.
However, for that plan, I had to fix the whole code base to be IWYU
compliant - which it now is.
This PR places all LMMS symbols into namespaces to eliminate any potential future name collisions between LMMS and third-party modules.
Also, this PR changes back `LmmsCore` to `Engine`, reverting c519921306 .
Co-authored-by: allejok96 <allejok96@gmail.com>
LMMS now properly builds and runs with Qt5. Various deprecated functions
had to be replaced like QString::toAscii()/fromAscii(). Also occurences
of FALSE/TRUE have been replaced with false/true.
LmmsStyle now derives from QProxyStyle and sets a style instance as base
style (Plastique for Qt4, Fusion for Qt5).
MOC files are not included anymore but added as regular source files.
What's missing is support for embedding VST plugins into a subwindow
inside LMMS on Linux/X11 due to missing QX11EmbedContainer class in Qt5.
Build instructions can be found in INSTALL.Qt5
Minimum version requirement for Qt4 has been raised to 4.6.0 for best
API compatibility between Qt4 and Qt5.
