* 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
