Made changes for C++, general usability

[samgubernick]

-Moved dynamic easing functions to dedicated file
-Added regular functions and namespaces
-Removed dependency from easing.cpp (now in easing_dynamic.cpp)
-Added decimals to whole numbers (1, 2, ... are now 1.0, 2.0, ...)
-Changed types to auto
-Removed leading and trailing spaces
-Changed header file format to .hpp
-Changed lowercase class names to capitalized first letter of words
-Added include guards
-Changed easing enum to enum class

[vedangjavdekar]

Any specific reason to have both the ifndef guard and the pragma once?

[TheRaffy]

Source: https://stackoverflow.com/questions/1143936/pragma-once-vs-include-guards
The reasons are :

#pragma once is not standard, so it is possible that some compiler don't provide the functionality. That said, all major compiler supports it. If a compiler don't know it, at least it will be ignored.
As there is no standard behavior for #pragma once, you shouldn't assume that the behavior will be the same on all compiler. The guards will ensure at least that the basic assumption is the same for all compilers that at least implement the needed preprocessor instructions for guards.
On most compilers, #pragma once will speed up compilation (of one cpp) because the compiler will not reopen the file containing this instruction. So having it in a file might help, or not, depending on the compiler. I heard g++ can do the same optimization when guards are detected but it have to be confirmed.

Using the two together you get the best of each compiler for this.

(I didnt know as well, but now I do :)