MAKE: allow more verbose build output

people can now run:
  make Q=
to get a the maximum of build output
MAKE: standardize install variables

- convert to autotools-like variables commonly used in build scripts
- respect DESTDIR (used for temporary install locations)
- fix symlink logic to work with DESTDIR
${foo##bar} is posix, see:
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
under "2.6.2 Parameter Expansion"
- quote all variables that can contain whitespace
(make does not take care of that!)
MAKE: respect LIBDIR variable

Some distributions do not use plain "lib", rather "lib64"
and "lib32". Allow to control this variable.
Merge pull request #1407 from gentoo/Makefile

Makefile improvements