I found tinyCAD addon the most helpful solution for this problem. It can be downloaded here:

https://github.com/zeffii/Blender_CAD_utils

To install it, unpack the archive and put "mesh_tinyCAD" dir and its contents into your Blender addon dir. Then you can enable it in User Preferences > Addons as usual.

To use it, just select intersecting edges, press W and select TinyCAD > TinyCAD XALL

I found tinyCAD addon the most helpful solution for this problem. It can be downloaded here:

https://github.com/zeffii/Blender_CAD_utils

You can install several ways but the easiest is to download the zip linked in the readme and use the Install from File option in UserPreferences > Addons. Then you can enable it as usual.

To use it, just select intersecting edges, press W and select TinyCAD > TinyCAD XALL