[Halld-offline] nightly builds on group disk now

[Mark M. Ito]

Folks,

Last week I changed the target disk for the nightly builds of sim-recon. 
Previously they had been built on the scratch disk; now they are being 
built on the Hall D group disk. The scratch disk has become a bit 
unreliable; subversion check-outs were failing roughly half the time lately.

The documentation on the wiki at

   
https://halldweb1.jlab.org/wiki/index.php/Nightly_Builds_of_GlueX_Software

has been updated to reflect this change.

One note: because of more limited space on the group disk, we will only 
be able to keep about three days of builds there at one time. On the 
other hand (a) the disk is backed up every night so any build can be 
recovered and (b) the disk is "snapshot'ed" so we will always have 
access to frozen copies from 1, 2, and 3 weeks ago without having to ask 
for recovery from backup.

Let me know if you have questions.

   -- Mark