- refactored scene_main to be able to share code between software and
  hardware renderers, while still sharing code between terminal software
  renderer and graphical software renderer
- made the hardware renderer use scene objects vertices and transforms,
  instead of hardcoded ones
- made the hardware renderer use the scene's camera
- made .obj parser create Vector3 instead of Vector4, which didn't made
  sense
- removed unnecessary std::
- lots of small changes

- fixed aspect ratio being the inverse of what it's supposed to be
- use std::chrono::high_resolution_clock instead of system_clock
- convert ellapsed time to float representing seconds
- renamed engine::math::Matrix4::projection to perspective
- use [0,1] instead of [-1,1] for the range of z values, to be aligned
  with vulkan
- added engine::math::Matrix4::{look_at,transpose}

- cleaned up the computation of the camera's matrix
- changed VertexData to being a struct which transmit data between the "vertex shader" and the "fragment shader"
- started working on keyboard and mouse controls
- added fov (field of view)
- changed quaternion to euler angles conversion, from zyx to zxy
- fixed computations of z coordinates in triangle rendering
- improved naming in the triangle rasterizer

- added quaternions and rewrote all rotations to use them
- added transforms to put all object transforms in a single place
- added Wavefront .obj file parser
- removed frame buffer's abstract class
- improved vectors, matrices, triangles, vertices and vertices data by putting all code in header file
- added vector's operations
- changed from NULL to nullptr
- miscellaneous improvements

- In the context of mesh definition, splited
  indices into vertex index, normal index and
  vertex data index to be able to specify
  different normals and vertex data for
  different faces using the same vertex

- Added renderer to unify frame buffers
- Added FrameBuffer class as a parent for frame buffers' classes
- Improved formatting in Makefile.am
- Added const modifier in Matrix4's methods