master updated (787969c -> 99d8892)

[Ludovic Courtès]

civodul pushed a change to branch master.

      from  787969c   http: Correctly set #:timestamp for non-finished builds.
       new  e0e2709   utils: Add 'unwind-protect'.
       new  99d8892   'with-store' and 'with-database' and written in terms of 
'unwind-protect'.


Summary of changes:
 src/cuirass/base.scm     | 25 ++++++++++++-------------
 src/cuirass/database.scm |  6 ++----
 src/cuirass/utils.scm    | 20 ++++++++++++++++++++
 3 files changed, 34 insertions(+), 17 deletions(-)