pkg-config .pc files: added .private versions of Libs and Required

To prevent top-level linking of all libraries.

Problem: ```pkg-config --libs toxcore``` returns all libraries that are
required by all libtox*.so libraries. This is wrong because for a
dynamically linked executable only top-level libraries need to be
supplied. ```pkg-config --libs --static toxcore``` should return all
libraries for the statically linked executable.

For example, the ToxBot https://github.com/JFreegman/ToxBot executable
uses pkg-config and is linked with the opus library, which is wrong.

Based on #533.

0 files changed, 0 insertions, 0 deletions