This improves sane library dependencies, as mandated
by debian policy. Some of the librt functions are in such
wide use, that we'd get them through transitive dependencies
anyway. But linking explicitly against a function adds the
DT_NEEDED for this library to our build artefacts. This is
correct, since we're actually using these functions ourselves,
making them into direct dependencies.
The XV-Viewer widget in our GUI uses four direct calls
to the X-Lib. This was discovered by strict dependency checking,
as mandated by new Debian policy
Note: this drops some backwards compatibility. We're targeting now
roughly the range between Ubuntu-Precise (LTS) and Debian/testing,
with Debian/stable as the reference system.
The naming scheme for Boost-Libraries was adjusted with Boost-1.42
for Unix-Platforms. Now the '-mt' suffix isn't included any more, but
the libraries available through the usual packaging mechanisms can be
assumed to be thread safe.
See also http://issues.lumiera.org/ticket/759
