[1405] Make default "flush" option for logging "true"

By default, the logging layer should now flush after each message.

src/bin/cfgmgr/plugins/logging.spec

@@ -57,7 +57,7 @@
                       { "item_name": "flush",
                         "item_type": "boolean",
                         "item_optional": false,
-                        "item_default": false
+                        "item_default": true
                       },
                       { "item_name": "maxsize",
                         "item_type": "integer",

src/lib/log/output_option.h

@@ -60,7 +60,7 @@ struct OutputOption {
 
     /// \brief Constructor
     OutputOption() : destination(DEST_CONSOLE), stream(STR_STDERR),
-                     flush(false), facility("LOCAL0"), filename(""),
+                     flush(true), facility("LOCAL0"), filename(""),
                      maxsize(0), maxver(0)
     {}
 

src/lib/log/tests/output_option_unittest.cc

@@ -29,7 +29,7 @@ TEST(OutputOptionTest, Initialization) {
 
     EXPECT_EQ(OutputOption::DEST_CONSOLE, option.destination);
     EXPECT_EQ(OutputOption::STR_STDERR, option.stream);
-    EXPECT_FALSE(option.flush);
+    EXPECT_TRUE(option.flush);
     EXPECT_EQ(string("LOCAL0"), option.facility);
     EXPECT_EQ(string(""), option.filename);
     EXPECT_EQ(0, option.maxsize);