Replace "SMeshBuffer.h" with "CMeshBuffer.h"

[omicron1100]

• Replaces references to SMeshBuffer.h with CMeshBuffer.h in header files
• Adds using namespace irr; to the corresponding .cpp files in /src
  • This will make it easier to remove using namespace irr from header files in the future
• Make namespaces more explicit (video::SColor to irr::video::SColor)
  • This will also make it easier to remove using namespace irr from header files in the future
• Organize header includes to better indicate what includes come from /irr directly
  • #include "irr_ptr.h" -> #include <irr_ptr.h> as an example
  • Moved irr includes so they are visually separate from other includes
• Delete SMeshBuffer.h

To do

This PR is Ready for Review.

[sfan5]

Make namespaces more explicit (video::SColor to irr::video::SColor)

• This will also make it easier to remove using namespace irr from header files in the future

I don't think we want this. The current way is fine, less visual clutter and faster to type.

[omicron1100]

Make namespaces more explicit (video::SColor to irr::video::SColor)

• This will also make it easier to remove using namespace irr from header files in the future

I don't think we want this. The current way is fine, less visual clutter and faster to type.

True, but I think we should aim to take using out of header files as it's bad C++ practice and would eliminate namespace poisoning.

Would it be acceptable to add something like namespace color = irr::color; to the top of the header files instead?

[omicron1100]

Oops, I didn't mean to push here

[sfan5]

True, but I think we should aim to take using out of header files as it's bad C++ practice and would eliminate namespace poisoning.

Would it be acceptable to add something like namespace color = irr::color; to the top of the header files instead?

This makes sense in principle, but Irrlicht is not an external library (anymore) and entirely under our control.
The irr namespace has very few direct members.

[omicron1100]

This makes sense in principle, but Irrlicht is not an external library (anymore) and entirely under our control. The irr namespace has very few direct members.

I see. Would the ultimate goal be to get rid of the irr namespace then?

[sfan5]

Dunno.

[appgurueu]

This PR adds a bunch of these (as well as namespace scene = irr:scene; namespace video = irr:video;) which are redundant, as there is still the using namespace irr; in irrlichttypes.h?

For now I would curtail the scope of this PR and simply get rid of them.

I would prefer it if this was just what the PR title currently says it is which is something like a clean 10 loc diff, but I'm fine with keeping the header cleanup in here (and maybe updating the PR title).