Refactored TraceReader to support plugins.
Added first version of offset plotter for POSIX, read() and write().

It requires traces to be written.

Example usag:
siox-inst posix dd if=/dev/zero of=./test bs=1M count=1000 conv=fdatasync

In this folder run:
siox-trace-reader --plugin AccessInfoPlotter

It will output the commands to execute for the creation of a graph per file.