Added task_1.c
Added task_2.c
Edited task_2.c
Fixed task_2.c counter
Added task_3.c
Added task_4.c
Added task_5.c
Added christmas_tree.c
Fixed formatting of christmas_tree.c
Added reverse_number.c
Removed unnecesary var from reverse_number.c
Merge pull request #92 from PlamenNeshkov/master

Homework 3+4