Adding verbose flag to 'save_' functions

[weslleyspereira]

Hi.

First of all, thank you for this helpful library.

I am using this library in a C++ project. Since the code runs in multiple threads, the printf's generated by the "save_" functions cause the output to largely increase in size. Discarding these outputs without changing the code is too difficult since the threads runs independently and share the STDOUT.

So, I propose the addition of verbose flags to the "save_" functions to control the output.
The default behavior has been preserved.

Sds.
Weslley.