take ganglia package version out of libganglia1's SONAME

Before this change, because of the -release option passed to libtool,
every libganglia1 package was binary incompatible with the previous one.

See the comment in configure.ac above LIBGANGLIA_MICRO_VERSION and
friends for how to increase version components on the shared library for
compatible and incompatible changes.
move the *.so symlink from libganglia1 to libganglia1-dev

The actual shared libraries remain in the run-time package (libganglia1),
but the installed build-time package (libganglia1-dev) is what determines which
SONAME will go into the NEEDED in a binary that links with -lganglia1.
Merge pull request #149 from jhatala/fix-versioning

don't make libganglia1 releases incompatible, move the *.so symlink to -dev.