Unify behavior of mode bits for files/directories.

Previously the prescribed behavior by chirp_reli.h mandated that only the user
executable bit could be set. However, the chirp_fs_local.c implementation
allowed setting group/other bits and the executable bit can only be changed if
the file is not a directory.

This commit explicitly documents the user may set group/other bits and the user
executable bit (for non-directories). All backend file systems implement this
except HDFS, which has no executable bit.
send project name to workers in response to 'name' message
check that project name matches upon worker connection
add --name-list option doc into Parrot doc.
Fixed bug affecting advancement to the next day
DeltaDB select, sfilter, project, treduce, pivot, dfilter(leaky)
dfilter hacked (with a memory leak) to prevent seg faults. Number comparisons possible in dfilter,sfilter. End Date-Time possible with select.
Added first version of static reducer.  The output is too chatty
and duplicates need to be eliminated.
Cleaned up build process to rely on dttools, except for the modified nvpair.
We will fix that later.
Pivot should stop on end of file.
Factored reduction operators out of static reducer.
Static reduce emits all updates at a common time, so only update
when a new timestamp is seen.
Added nvpair.h back, pivot handles deltas (other than creates) now.
Accept and generate .Log End. events.
Switched to floating point math.
Fixed stray = in log output.
Fixed whitespace error in emitting reduced key.
Cleaned up pivot, it now requires a list of columns on the command
line, so that you get a fixed ordering for plotting.
Removed one hack from nvpair.c, one remaining.
Fix number output issues.
Removed debugging.