[Lazarus] CHM help package

[Marco van de Voort]

On Mon, Dec 11, 2017 at 06:32:45PM +0100, Werner Pamler via Lazarus wrote:
> I cloned your repo on my HD, and went through it step by step while 
> always trying to build lhelp, I could remove everything from the folder 
> chm except for these units: chmfifimain, chmreader, chmsitemap, chmtypes 
> (and chmobjinstance.inc). 

I walked through chmreader, and found one minor fix, a comparison of a filename
parameter with an extension should be lowercase. Fixed in r37714