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More ignored extensions
add: Basic main()
add: GFX Module
add: List Module

Implements an intrusive circular double liked list.
add: Render list to gfx module
add: list_entry macro
     (shamelessly copied from linux kernel)
add: Macros for list iteration (with safe delete version)
oops: Fix case in comment
add: Random Number Generator (based on xorshift128 algorithm)
add: Sprite renderer management

add: Basic render function

oops: Erroneus char in list_entry macro (cut & paste leftover)
oops: list_is_empty should return int (was void)
oops: erroneus char in list_entry macro reappeared (cut & paste leftover)
add: Sprite management

add: Sprite and render lists
add: GFX subsystems initialization
add: Application module
Rendering Loop done:

 * clear
 * draw
 * flip buffers
add: Sprite intialization routines

add: Shutdown subsystems
Check if node is valid (i.e. not an empty list) before deleting from list
oops: Wrong variable in list_foreach_safe