[WIP] Module Support

[krakjoe]

This is a WIP for module support, and depends on CMake PR

The basic idea is that phpspy should export handler pointer, LD_PRELOAD is used to load the module and set that handler ...

TODO:

• CMake build for module
• Support standard makefile build ?
• Have phpspy detect when handler is not builtin, force pid mode only ?

This is nothing like complete, but a thing to get the conversation started ...

Open questions:

• Depend on libdl so that phpspy may load the modules (no preload)
• Support makefiles (ewww)
• Define module structure with individual handlers for each event, so that a module may set handlers for events it intends to process.

Implements #60