taglib: bump to 1.7

Bump the version of taglib to 1.7. This version does not any longer
ship with a configure script so convert the package from autotargets
to cmaketargets.

The 1.7 version offers optional support for MP4 and WMA files.
Expose these options in buildroot.

[Peter: drop unneded dependencies, keep target install, fix Config.in indent]
Signed-off-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>