[#45] Updated recv so main thread will write data

The update time was not being updated due to the thread which closes the
file not actually writing data.

Changes:

1.  Only start N - 1 threads which read data from circular buffer and
writes to file.

2.  Main thread also reads data from circular buffer and writes to file.

3.  Main thread starts another thread to read from network before doing
its reading/writing.

4.  Added a condition variable to make sure the main thread handles at
least one chunk of bytes.

tmp

CMakeLists.txt

@@ -24,7 +24,7 @@
 cmake_minimum_required (VERSION 3.11 FATAL_ERROR)
 
 find_package(IRODS 4.2.11 EXACT REQUIRED CONFIG)
-set(IRODS_CLIENT_REVISION "1")
+set(IRODS_CLIENT_REVISION "2")
 set(IRODS_CLIENT_VERSION "${IRODS_VERSION}.${IRODS_CLIENT_REVISION}")
 
 set(IRODS_CLIENT_NAME "irods-gridftp-client")