Remove m4 and rely on autofoo to pull them in
Remove pregenerated doc files, will be generated on every build
Remove ltmain.sh, autofoo will bring it in
Add update-icon-cache config option for makedistcheck

Otherwise the cache file is left behind and make distcheck fails.
Rename INCLUDES to AM_CPPFLAGS in Makefile
Remove obsolete distro folder
Merge pull request #187 from infirit/1.6

Add disable-icon-update for distcheck / various cleanups