My repository clone:

hg clone https://julientendero-adullactproject.googlecode.com/hg/ 
julientendero-adullactproject  

Purpose of code changes:

manage automatically the conflicts between tasks considering their priority.
Adjust the tasks position in the time when a resource is overloaded.

The automatic adjustment is performed only when the priorities of conflicting 
tasks are different.

For example, when two tasks are in conflict and one of them has a higher 
priority than the other, it is the task with the lowest priority that will be 
lengthened in time by being assigned an area cut-off period where conflict 
takes effect. It is indicated for the task elongated, the number of days added 
and tasks corresponding to each conflicting extension (requires to display the 
duration of tasks in the properties diagram Gantt).

However, when the two spots have equal priority level, it is to the user to 
adjust the conflict according to his wish, by this way it is always possible 
for the user to manually adjust the tasks in case of conflict.

Where an adjustment is made, it is possible to go back by changing the priority 
level (so that there is a equal level priority) or simply by removing the 
conflict (remove resources to the task concerned or change the units of a 
resource for a task).

When reviewing my code changes, please focus on:

net.sourceforge.ganttproject.task.TaskImpl.java
net.sourceforge.ganttproject.task.TaskProperties.java