[Harbour] hbmk2 new extensions

[Szakáts Viktor]

> My two cents for convincing you
> IMO is right having P for Project instead Parameter
> sound very good  Hbp for traditional project file
> and hbl,(hbc,hbx) for Library and other Common eXternal parameter
> I imvite other harobour use explain point of view
> more point on view
> more better harbour version

If we can find a better expression for Harbour Package
/ Library / Parameter, and a better extension than
.hbl/.hbp I can think about it.

I don't like .hbx (which has too many and confusing
connotations with xhb).

.hbc doesn't tell much about the purpose ("common"
what?). It would be optimal to have _one_ such extension
to keep things simple and elegant. For me the previous
state was much closer to that.

Brgds,
Viktor