Add PD after the initial configuration

[hahnnicholas]

Add the capability to add PD's in the CP after the initial initialization.
This can be used to add devices in run time.

[sidcha]

After fixing the realloc() bug, and fixing the broken code formatting (see style guide), I will take a closer look at this PR.

[sidcha]

Add the capability to add PD's in the CP after the initial initialization

Please add some motivation/problem-statement which lead you to make this change. PDs don't need to be added at runtime in most cases. Knowing why you are doing what you are doing, helps me better evaluate your change.

[hahnnicholas]

Hi, thanks for your time.
It's not a issue but more a design related thing.
Sometimes applications are reader oriented rather then osdp PD oriented, so as in my case.
This implies that the application build the readers during initialization as they are configured in the database.
Every time a reader are built, the reader factory needs to check wich type this reader are and add their addrs to the CP to be managed.
In my case, it's easier to add pd's to the cp on the fly than have to wait for all the inicialization to full fill an array (that I don't know the size previously cause it are configured in the database) to only after that start the CP process.

[sidcha]

Posting these comments just for posterity. Most of these are nits, and since I was already reviewing them locally, just decided to address them locally to avoid a back-and-forth.

[sidcha]

Thanks for the PR.

[hahnnicholas]

Thanks for your help, time and kindly review.