all: Refactoring work with time using boost::chrono

Now the library has two clocks: time::steady_clock and
time::system_clock, following (boost|std)::chrono.  In addition to
standard now() method, the library contains several helpers to convert
to/from UnixTimestamp (microsecond resolution) and IsoString (optional
microsecond resolution).  The IsoString conversions use
boost::posix_time routines, since boost::chrono supports extended IO
support only starting boost version 1.52 (Boost Chrono V2).

This commit breaks compatibility with previous API.  All time-related
Data/Interest calls must explicitly use time units to specify
FreshnessPeriod/InterestLifetime.

Brief usage/conversion guide:

- creation of time units does not support double/float types.  If
  necessary to create time unit from double, ``ndn::duration<double>`` (for
  seconds) needs to be used instead.  In some cases, this would also
  require ``ndn::duration_cast``, if the target is not ``ndn::nanoseconds``.
- ndn::getNow, ndn::ndn_getNowMilliseconds, ndn::time::now are all
  removed in favor of the now() method in a specific clock:

    * time::system_clock::now();
    * time::steady_clock::now();

- When necessary to convert system_clock::TimePoint to unix timestamp,
  ``time::toUnixTimestamp`` can be used.  This method return number of
  milliseconds since UNIX epoch as ``ndn::time::milliseconds`` type.
  Use count() method to obtain number as an integral value.

Change-Id: Icd688bc6766e008d60c3d2888173627874526e47
Refs: #1152
diff --git a/src/security/sec-public-info-sqlite3.cpp b/src/security/sec-public-info-sqlite3.cpp
index 16041d3..aeb34dd 100644
--- a/src/security/sec-public-info-sqlite3.cpp
+++ b/src/security/sec-public-info-sqlite3.cpp
@@ -365,9 +365,11 @@
 //   sqlite3_bind_text(statement, 3, identityName, SQLITE_STATIC);
 //   sqlite3_bind_text(statement, 4, keyId, SQLITE_STATIC);
 
-//   // Convert from milliseconds to seconds since 1/1/1970.
-//   sqlite3_bind_int64(statement, 5, static_cast<sqlite3_int64>(certificate.getNotBefore() / 1000));
-//   sqlite3_bind_int64(statement, 6, static_cast<sqlite3_int64>(certificate.getNotAfter() / 1000));
+//   // Convert from time::milliseconds to time::seconds since 1/1/1970.
+// sqlite3_bind_int64(statement, 5, static_cast<sqlite3_int64>(
+//                                    time::toUnixTimestamp(certificate.getNotBefore()).count()));
+// sqlite3_bind_int64(statement, 6, static_cast<sqlite3_int64>(
+//                                    time::toUnixTimestamp(certificate.getNotAfter()).count()));
 
 //   sqlite3_bind_blob(statement, 7, certificate.wireEncode().wire(), certificate.wireEncode().size(), SQLITE_STATIC);
 
@@ -420,9 +422,10 @@
   sqlite3_bind_text(statement, 3, identity.toUri(), SQLITE_TRANSIENT);
   sqlite3_bind_text(statement, 4, keyId, SQLITE_STATIC);
 
-  // Convert from milliseconds to seconds since 1/1/1970.
-  sqlite3_bind_int64(statement, 5, static_cast<sqlite3_int64>(certificate.getNotBefore() / 1000));
-  sqlite3_bind_int64(statement, 6, static_cast<sqlite3_int64>(certificate.getNotAfter() / 1000));
+  sqlite3_bind_int64(statement, 5, static_cast<sqlite3_int64>(
+                                     time::toUnixTimestamp(certificate.getNotBefore()).count()));
+  sqlite3_bind_int64(statement, 6, static_cast<sqlite3_int64>(
+                                     time::toUnixTimestamp(certificate.getNotAfter()).count()));
 
   sqlite3_bind_blob(statement, 7, certificate.wireEncode().wire(), certificate.wireEncode().size(), SQLITE_TRANSIENT);
 
@@ -447,7 +450,8 @@
   if (res == SQLITE_ROW)
     {
       shared_ptr<IdentityCertificate> certificate = make_shared<IdentityCertificate>();
-      certificate->wireDecode(Block((const uint8_t*)sqlite3_column_blob(statement, 0), sqlite3_column_bytes(statement, 0)));
+      certificate->wireDecode(Block((const uint8_t*)sqlite3_column_blob(statement, 0),
+                                    sqlite3_column_bytes(statement, 0)));
       sqlite3_finalize(statement);
       return certificate;
     }