khn.h : include KPMLib.h
KHNClient: display an error message when a topic is not found in HELPNDX
KPMLib.h is not a standard header in a point of view of khn
KHelpNdxFile: search a topic case-insensitively
KHelpNdxFile: compare a string from pos not from 0
Calculate a client area size in according to a font size
Restore a window position
cosmetics
KHNClient: select a text when an entry field has a focus
KHNClient: minimize khn only if a topic is found in HELPNDX