* fixed a bug in hierarchal shematics where a loop (e.g. same file included at different points in the
hierarchy) would cause infinite memory use.
* added a edit footprint hotkey to eeschema, since it seems I'm always editing '0603' '0402' etc. on the
common components, and it was difficult to edit this information before.
added buttons for insert and replace module in the module editor
with a new bitmap. restored JP's original functionality for the insert
button, replace linked to the new code.