* Fixed a bug in PCB_EDIT_FRAME::loadFootprints when no footprint libraries
are found when attempting to load footprints.
* Add a warning to PCB_EDIT_FRAME::loadFootprints to inform the user when
a footprint library file cannot be found in any of the standard library
search paths.
* Changed FOOTPRINT_INFO::m_padCount to unsigned to prevent signed/unsigned
comparison compiler warnings.
* Put NestedSpace() function in netlist_reader.cpp inside conditional debug
build statement to prevent warning in release builds.
* Use version of DateAndTime that returns a wxString and delete the
version that takes a char* as it is no longer required.
* Merge StrNumICmp() and StrLenNumICmp() into StrLenNumCmp() to create a
single function for comparing strings with integers and remove a lot
of duplicate code.
* Remove unused strupper from string.cpp.
* Use wxArrayString for sorting the EDA_LIST_DIALOG contents.