Qbs: Unify naming of actions

Change-Id: I82c697bfdf191d915009410b783c712dd741d0e8
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Qbs: Rename m_current(Project|Target|Node) to m_selected*

These are the nodes selected in the project tree, not the current/startup
project or things related to that.

Change-Id: I5860ccf9cc3a088a1bc047f4a2b6a909c72d4eca
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Qbs: Rename reparseCurrentProject method to reparseSelectedProject

Change-Id: Ic574894d5ba993cb9b2d3dc2731ce169f0d66581
Reviewed-by: Daniel Teske <daniel.teske@digia.com>