Subject: [PATCH] Adding lws_config.h to list of installed headers.

The lws_config.h is generated based on configuration
options for the build process. In order to write
applications which compile code depending of the
presence of a feature (like the test-server does)
this header file needs to be installed.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>