Fix MakeFile

[cmft]

The generated library is wrong (has undefined symbol) since tango libraries
are not set.

Add them and a linker flag to report this error. When creating a shared object,
this flag will cause the link to fail if there are unresolved symbols

[lorenzopivetta]

I do not think you need to link this .so against the TANGO libraries... symbols will be resolved at runtime

[gscalam]

I dont't know,
@chedburgh and @bourtemb what do you think and what about libhdbpp-cassandra ?

[cmft]

Hi all,
we detected this problem when we tried to import this library from python.
If you try to compile the library with -z,defs flag without adding the libraries, it reports the linking problems.

The ldd cmd does not show the link with tango libraries

$ ldd /usr/lib/x86_64-linux-gnu/libhdb++mysql.so.6.0.0 
        linux-vdso.so.1 (0x00007fff7f133000)
        libmariadbclient.so.18 => /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18 (0x00007f86c6093000)
        libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f86c5e76000)
        libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f86c5c5c000)
        libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f86c5a58000)
        libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f86c56d6000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f86c53d2000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f86c51bb000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f86c4e1c000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f86c68fc000)

[lorenzopivetta]

At a quick look, according to the gcc man page, the -z "keyword" is an option that gets passed straight to the linker. That is, you ask the linker to resolve against the known library paths. Still, I'm in the idea this is not required at this stage. Tango (and system) libraries get resolved when the linker is instructed to produce the final object.