that is a part of the libtool package. Updated Makefile dependencies.
TODO: check if we can get rid of the ltdl*.* files (this would be possible if
the ltdl library is always available if libtool is present).
- ALSA stuff moved from soundlnx.* to new soundalsa.* files
- SB16 / ES1370: including specific sound driver headers not necessary
- updated dependencies
- TODO #1: update MSVC workspace files
- TODO #2: these 'device classes' could be moved to subdirectories, too:
- pci (when we have more than one chipset)
- display (when we have one more device and vga / cirrus cleaned up)
