ChronoLog errorcodes.h should be exposed in the client include directory

[ibrodkin]

chronolog_errcode.h file should be cleaned up and exposed to the client

All the error codes that are used in client API and should be exposed in Client include directory. There should a printable explanation of what the error means in that header file as well. I suggest implementing it as an array of strings keyed by the error code enumeration.

WE can add a "server side" set of error codes that we would be using and adding to without the need to update the client library version every time we need to add another ERROR_code.