Remove Boost conditional compilation.

Boost is currently at version 106200 in the depends subsystem
so it is safe to remove code the refers to earlier versions.

This closes #2445

src/scheduler.cpp

@@ -20,13 +20,6 @@ CScheduler::~CScheduler()
 }
 
 
-#if BOOST_VERSION < 105000
-static boost::system_time toPosixTime(const boost::chrono::system_clock::time_point& t)
-{
-    return boost::posix_time::from_time_t(boost::chrono::system_clock::to_time_t(t));
-}
-#endif
-
 void CScheduler::serviceQueue()
 {
     boost::unique_lock<boost::mutex> lock(newTaskMutex);
@@ -45,20 +38,13 @@ void CScheduler::serviceQueue()
             // Wait until either there is a new task, or until
             // the time of the first item on the queue:
 
-// wait_until needs boost 1.50 or later; older versions have timed_wait:
-#if BOOST_VERSION < 105000
-            while (!shouldStop() && !taskQueue.empty() &&
-                   newTaskScheduled.timed_wait(lock, toPosixTime(taskQueue.begin()->first))) {
-                // Keep waiting until timeout
-            }
-#else
             // Some boost versions have a conflicting overload of wait_until that returns void.
             // Explicitly use a template here to avoid hitting that overload.
             while (!shouldStop() && !taskQueue.empty() &&
                    newTaskScheduled.wait_until<>(lock, taskQueue.begin()->first) != boost::cv_status::timeout) {
                 // Keep waiting until timeout
             }
-#endif
+
             // If there are multiple threads, the queue can empty while we're waiting (another
             // thread may service the task we were waiting on).
             if (shouldStop() || taskQueue.empty())

src/util.cpp

@@ -911,10 +911,6 @@ std::string LicenseInfo()
 
 int GetNumCores()
 {
-#if BOOST_VERSION >= 105600
     return boost::thread::physical_concurrency();
-#else // Must fall back to hardware_concurrency, which unfortunately counts virtual cores
-    return boost::thread::hardware_concurrency();
-#endif
 }
 

src/wallet/walletdb.cpp

@@ -968,11 +968,7 @@ bool BackupWallet(const CWallet& wallet, const string& strDest)
                     pathDest /= wallet.strWalletFile;
 
                 try {
-#if BOOST_VERSION >= 104000
                     boost::filesystem::copy_file(pathSrc, pathDest, boost::filesystem::copy_option::overwrite_if_exists);
-#else
-                    boost::filesystem::copy_file(pathSrc, pathDest);
-#endif
                     LogPrintf("copied wallet.dat to %s\n", pathDest.string());
                     return true;
                 } catch (const boost::filesystem::filesystem_error& e) {