Possible issues with libinstpatch when initialized two times via shared objects

[jjceresa]

This refers to #70.

Requirement:
For libinstpatch intended to be called by an application, the developer must be careful that there will be ONLY ONE instance of libinstpatch loaded when the application is running. Otherwise this will lead to issue described by #70.

To ensure a correct behaviour it is recommended to build libinstpatch as a single dynamic shared object, then linking the application to this libinstpatch shared object.

Of course as far the developer is aware