xdm: Changes to 'master'

[Alan Coopersmith]

 README              |   14 ++++++++++++++
 config/Makefile.am  |   14 +++++++++++++-
 config/Xreset.cpp   |    2 +-
 config/Xstartup.cpp |    2 +-
 configure.ac        |   44 ++++++++++++++++++++++----------------------
 5 files changed, 51 insertions(+), 25 deletions(-)

New commits:
commit cdc7b575452a621fb467004d607288af6dd4c802
Author: Alan Coopersmith <alan.coopersmith at oracle.com>
Date:   Tue Nov 4 21:44:05 2014 -0800

    Only pass -u & -w args to sessreg if --with-{u,w}tmp-file=path specified
    
    If not specified, let sessreg use its builtin defaults instead of
    replicating the logic here (and possibly getting it wrong), especially
    since in sessreg-1.0.8 and earlier, using the -u & -w flags forces
    the use of the utmp/wtmp code and not the newer utmpx/wtmpx code.
    
    If --without-{u,w}tmp-file or --with-{u,w}tmp-file=none is specified,
    pass "none" as arguments to sessreg to disable writing to that file.
    
    v2: better handling of --with & --without arguments when not passing path,
    add documentation of the 3 choices to README
    
    Signed-off-by: Alan Coopersmith <alan.coopersmith at oracle.com>