Use simplified charWidth function provided by @TurbulentCalm (Issue #4)
Change "width field" of supplied variable width fonts from arbitrary values (mostly 10) to values that approximate "wide" font spacing - may still be too wide. (Issue #4)
Fix bug causing extended ASCII characters not to display (as per bug report at http://forum.freetronics.com/viewtopic.php?f=37&t=5730 )