Removed unnecessary dependency on libpng, fixed header check and include

guacamole/proxy/configure.in

@@ -10,12 +10,10 @@ AC_PROG_CC
 # Checks for libraries.
 AC_CHECK_LIB([dl], [dlopen],, AC_MSG_ERROR("libdl is required for loading client plugins"))
 AC_CHECK_LIB([guac], [guac_get_client],, AC_MSG_ERROR("libguac must be installed first"))
-AC_CHECK_LIB([png], [png_write_png])
 AC_CHECK_LIB([pthread], [pthread_create],, AC_MSG_ERROR("POSIX threads (libpthread) must be installed"))
 
-
 # Checks for header files.
-AC_CHECK_HEADERS([netinet/in.h stdlib.h string.h sys/socket.h syslog.h unistd.h])
+AC_CHECK_HEADERS([netinet/in.h stdlib.h string.h sys/socket.h syslog.h unistd.h guacamole/client.h])
 
 # Checks for library functions.
 AC_FUNC_MALLOC

guacamole/proxy/src/daemon.c

@@ -30,7 +30,7 @@
 #include <errno.h>
 #include <syslog.h>
 
-#include <client.h>
+#include <guacamole/client.h>
 
 typedef struct client_thread_data {