Properly separate files as we will not have only one single base class
for all elements as we used to with 0.10, but the same way it is done
with ladspa, we subclass GstAudioFilter, GstBaseSource etc...
https://bugzilla.gnome.org/show_bug.cgi?id=678207
This makes sure that the headers from the source tree are taken and not
accidentially installed system headers in the case of builddir!=srcdir.
Fixes bug #602161.
Install the headers, version the library with @GST_MAJORMINOR@,
add all required libraries to _LIBADD instead of _LDFLAGS,
and add GST_*_LDFLAGS to _LDFLAGS.
Fixes bug #594715.
- Separate gstsignalprocessor into a separate library (not sure if this
is in the right place, but it works for now anyway)
- Create LV2 element based on LADSPA element, port most discovery
functionality
