buildhistory: Restore parsing time optimalization

* it was added in:
  http://git.openembedded.org/openembedded-core/commit/meta/classes/buildhistory.bbclass?id=540a2a30be21c3eca4323efbe91e7dcfc31a4c97
* then accidentally removed in:
  http://git.openembedded.org/openembedded-core/commit/meta/classes/buildhistory.bbclass?id=6db6c74f2876df7a183990426bb4262972966441

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
libxml2: Explicitly enable zlib support

The zlib support is a must if you are using RPM backend. So this
explicitly enable it and adds a comment in the recipe to avoid its
removal by mistake.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
autogen-native: inherit pkgconfig to fix a build failure

This patch is to inherit pkgconfig to fix a build
failure.

Signed-off-by: Christopher Larson <kergoth@gmail.com>
Signed-off-by: Shrikant Bobade <Shrikant_Bobade@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>