Remove unused functions

[Vulpine05]

Description of the Change Browsing through the code, I have found several functions defined in header files that Visual Studio found did not have an associated function nor inline code. Since these functions do not exist, this PR removes them.

I have broken up the PR into three commits; each commit is for a subfolder (client, manager, and lib).

This PR does not clean up ALL unused functions. There were some functions that were empty constructors that I didn't feel comfortable removing. Another thing I discovered were some functions were noted by Visual Studio as not defined, but the function was written in one or more preprocessor definitions. With that said, I tried to carefully remove only functions that were obvious to me that weren't defined. Thank you in advance for reviewing!