Bug#794913: libphonenumber6: please use libboost-date-time 1.57 or 1.58 ASAP

[jnqnfe]

Control: severity -1 critical
Control: tags -1 + security

As described in the bug report, the libboost-date-time1.55.0 package is
incompatible with GCC5 and will not be fixed, requiring a transition to
1.57 or 1.58. Unfortunately the GCC5 transition has already been taking
place on Sid (with libstdc++6 specifying a break against libboost-date
-time1.55.0), despite libreoffice and it's libphonenumber6 and libcmis
-0.5-5 dependencies not being ready for a 1.57/1.58 transition. This
has resulted in Sid users being unable to install a bunch of updates
for the past few days, now including security updates (e.g. the CVE
-2015-4495 emergency patch to iceweasel). Hence I'm taking the liberty
of pushing up the severity on this. We need to get libreoffice and it's
dependencies transitioned to a boost 1.57/1.58 ASAP.