Support varlist in KReturn2

Patch by: Roman Rakus <rrakus@redhat.com>
Create proper .so symlinks for libkonkretmof
Merge pull request #1 from kkaempf/konkretmof_soversion

Create proper .so symlinks for libkonkretmof
Define _GNU_SOURCE if not defined
Add support for embedded instances
Generate header for EmbeddedInstance class
Enable using direct calls in KDefaultGetInstance
Fix instance to string conversion
Fix possible integer overflow
Set format(printf) attribute to __KReturn2 function

This way, users of this function will get notified when they use options
(like invalid number of formatted variables).
Suppress warning about anonymous variadic macros in C++98
Merge branch 'master' into proxy