SOA-EDIT: fix INCEPTION-INCREMENT handling
Fix false libtool variable: _LIBS -> _LIBADD

_LIBS is not a libtool variable, thus the remotebackend module does not
get linked to libcurl. Fix this by using _LIBADD instead.
Use LUA_CFLAGS and LUA_LIBS instead of hardcoded paths.
Restructure system PolarSSL detection

Based on the chapter "Automatic Dependencies with AC_ARG_WITH" of the
Autotools Mythbuster eBook, fix the system PolarSSL detection and
recognize both --with/without-system-polarssl properly. Furthermore,
set the HAVE_LIBPOLARSSL automake variable conditionally. Otherwise pdns will
use the included headers but link against the system polarssl resulting in
subtle breaks.
Replace PolarSSL-conditionals in Makefile.am and trust the include dirs

Different ways of using the bundled PolarSSL have been used (-L.. vs
if/then/else). Replace this by defining POLARSSL_CFLAGS/_LIBS/_SUBDIR in
configure.ac and use that in all makefiles. Remove includes based on the
preprocessor HAVE_LIBPOLARSSL definition and trust the CFLAGS set in the
environment to point to the correct directory for the PolarSSL include.
Only commit & purge cache when we have changed
NIt
Correct changed record numbers for add/update
Correctl changedRec for deleting RRs
changedRecords is now a uint and with a normal name again.
Intending
Fix truncating bug
Merge pull request #921 from cyclops1982/429

429
Merge pull request #911 from stbuehler/fix-inception-increment

SOA-EDIT: fix INCEPTION-INCREMENT handling
Merge pull request #922 from cyclops1982/rfc2136

Small improvements on change tracking for rfc2136
improve make distclean
drop config.h from make dist
Merge pull request #825 from dev-zero/master

Various build system fixes (3rd try)
remove version_generated.h on clean
actually notice timeout during AXFR retrieve, thanks hkraal