Distinguish between tasks in different projects with the same label

[mrichar1]

Currently task nodes are drawn using the task description as the label. This causes tasks with the same description to be 'merged' into a single task. Ideally the tasks should be identified by their UUID to prevent such conflicts.

Steps to reproduce:

task add proj:server1 "Update software"
task add proj:server2 "Update software"

task status:pending export |task2dot

digraph dependencies {layout="fdp"; splines="ortho"; size="30,30"; bgcolor="#111519";
"Update software
" -> "server1"[color="#aa2211"]
"Update software
"[id="activate('task', 'Update software
')"][shape="box"][color="white"][fontcolor="white"][style="rounded,filled"][fillcolor="#222299"][fontsize="16"]
"server1"[id="activate('project', 'server1')"][shape="diamond"][penwidth="2pt"][color="#22ff22"][fontcolor="#ffffff"][style="filled"][fillcolor="#115500"]
"Update software
" -> "server2"[color="#aa2211"]
"Update software
"[id="activate('task', 'Update software
')"][shape="box"][color="white"][fontcolor="white"][style="rounded,filled"][fillcolor="#222299"][fontsize="16"]
"server2"[id="activate('project', 'server2')"][shape="diamond"][penwidth="2pt"][color="#22ff22"][fontcolor="#ffffff"][style="filled"][fillcolor="#115500"]
}