Strict @property syntax compliance.

This enables the test suite to build with the -property switch enabled.

std.cpuid: vendor()/processor() have not been converted to properties in accordance to core.cpuid.
std.xml: Element.text() cannot be a property due to the optional parameter.

std/exception.d

@@ -863,7 +863,7 @@ class ErrnoException : Exception
     uint errno;                 // operating system error code
     this(string msg, string file = null, size_t line = 0)
     {
-        errno = getErrno;
+        errno = getErrno();
         version (linux)
         {
             char[1024] buf = void;