Flame fragment shader!

This update includes the following changes and additions:

• New shader called Flame Raymarching .
  • It uses rendering technique called raymarching that, in this case, allows to achieve nearly photo realistic effect.
  • The number of raymarching iterations can be controlled by the corresponding UISlider. Note that the higher the number of iterations the more likely your device is gonna burn 😜
• Implemented UI controls for Flame shader.
• Decreased iOS deployment target from 11 to 10.
• Fixed small issues related to rounded corners with UIButton components.