Fix the larger problem that was hiding behind the build problem of set_haiku_revsion on FreeBSD:

* the length of the sHaikuRevision character array symbol needs to be set explicitly,
  as using either _SYS_NAMELEN or sizeof(utsname::version) will only return the values
  for the host, which may not match ours, thus potentially causing problems when using
  sHaikuRevision
* add headers/private/system_revision.h which defines SYSTEM_REVISION_LENGTH to 128
* adjust definitions of sHaikuRevision in libroot and kernel accordingly
utsname::version is shorter than SYSTEM_REVISION_LENGTH, but that doesn't cause any harm
until we have indeed switched to a DVCS (in which case longer revision strings will be 
cut off by 'uname').


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@41421 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/system/system_revision.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright 2011, Oliver Tappe <[email protected]>.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _SYSTEM_SYSTEM_REVISION_H
+#define _SYSTEM_SYSTEM_REVISION_H
+
+
+/** The length of the system revision character array symbol living in libroot
+    and the kernel */
+#define SYSTEM_REVISION_LENGTH 128
+
+
+#endif	/* _SYSTEM_SYSTEM_REVISION_H */