In commit 7cb754dd a call to wxMilliSleep(50) was removed (because it created
lag in editing) but this removal created a 100% CPU core usage.
Using a much small sleep time (1ms) fixes these issues.
No longer auto-set the Footprint field when setting the FPID
This avoids forcing the field to the footprint name in the
library editor, which gets in the way. This doesn't specifically
inhibit the use of the field, and doesn't interfere with fields
users may have set manually (it can be cleared manually if
wished).
Removing the footprint field entirely either from all footprints
or from footprints in fpedit is quite a bit more invasive to
existing designs.
