(Maint) Restore soloris-11.cfg

The cherry-pick of configuration changes from master included this file,
but I didn't think it was used because it didn't previously exist on
this branch. However, there appears to be a jenkins job that tries to
use it.
(packaging) Update VERSION to 1.3.1-rc1
Merge tag '1.3.1-rc1'

1.3.1-rc1

* tag '1.3.1-rc1':
  (packaging) Update VERSION to 1.3.1-rc1
  (Maint) Restore soloris-11.cfg