Improve the configure checks.

ConfigureChecks.cmake

@@ -23,7 +23,12 @@ endif(CMAKE_COMPILER_IS_GNUC)
 # HEADER FILES
 check_include_file(pty.h HAVE_PTY_H)
 check_include_file(terminos.h HAVE_TERMIOS_H)
-check_include_file(wspiapi.h HAVE_WSPIAPI_H)
+if (WIN32)
+  check_include_file(wspiapi.h HAVE_WSPIAPI_H)
+  set(HAVE_GETADDRINFO TRUE)
+  set(HAVE_GETHOSTBYNAME TRUE)
+  set(HAVE_SELECT TRUE)
+endif (WIN32)
 
 set(CMAKE_REQUIRED_INCLUDES ${OPENSSL_INCLUDE_DIRS})
 check_include_file(openssl/aes.h HAVE_OPENSSL_AES_H)
@@ -34,11 +39,7 @@ check_include_file(openssl/des.h HAVE_OPENSSL_DES_H)
 
 # FUNCTIONS
 check_function_exists(cfmakeraw HAVE_CFMAKERAW)
-if (WIN32)
-  set(HAVE_GETADDRINFO TRUE)
-  set(HAVE_GETHOSTBYNAME TRUE)
-  set(HAVE_SELECT TRUE)
-else (WIN32)
+if (UNIX)
   check_function_exists(getaddrinfo HAVE_GETADDRINFO)
   if (NOT HAVE_GETADDRINFO)
     check_library_exists("socket" "getaddrinfo" "" HAVE_LIB_GETADDRINFO)
@@ -52,7 +53,7 @@ else (WIN32)
   check_function_exists(poll HAVE_POLL)
   check_function_exists(select HAVE_SELECT)
   check_function_exists(regcomp HAVE_REGCOMP)
-endif (WIN32)
+endif (UNIX)
 
 # LIBRARIES
 if (CRYPTO_FOUND)