They don't define a KiCad string class, so the header file name was
somewhat misleading. But the fact that they didn't match definitely
made coding more difficult.
Added checks to StrCmpNum() function in common/sting.cpp to prevent
iterating past the end of the sting. Also removed length of string
parameter since it did not seem to be used anywhere.
Fixes lp:1818157
https://bugs.launchpad.net/kicad/+bug/1818157
This is not logic specific to MODULE. Breaking it out to
kicad_string.h acheives:
* Slimming of the MODULE interface
* Enables reuse of the function
* Enables testing of the function
Also add a test under qa_common for this function.
Jeff Young
Sylwester Kocjan
Wayne Stambaugh
Seth Hillbrand
John Beard