Add bottom status bar with git build info and compile time

Source/BuildInfo.cpp

@@ -0,0 +1,32 @@
+#include "BuildInfo.h"
+#include <cstdio>
+#include <cstring>
+
+std::string getBuildInfoString() {
+    // Actual compilation time from compiler built-ins.
+    // __DATE__ -> "Mmm dd yyyy", __TIME__ -> "HH:MM:SS"
+    const char* date = __DATE__;
+    const char* time = __TIME__;
+
+    static const char* months[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+                                   "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
+    char mon[4] = {0};
+    int day = 0, year = 0, hh = 0, mm = 0, ss = 0;
+    std::sscanf(date, "%3s %d %d", mon, &day, &year);
+    std::sscanf(time, "%d:%d:%d", &hh, &mm, &ss);
+
+    int mi = 1;
+    for (int i = 0; i < 12; ++i)
+        if (std::strcmp(mon, months[i]) == 0) { mi = i + 1; break; }
+
+    char buf[64];
+    std::snprintf(buf, sizeof(buf), "%04d-%02d-%02d__%02d-%02d-%02d",
+                  year, mi, day, hh, mm, ss);
+
+    std::string s = std::string("build ") + CHROMAFLOCK_GIT_HASH
+                    + " (" + CHROMAFLOCK_GIT_BRANCH + ")";
+    if (CHROMAFLOCK_GIT_DIRTY)
+        s += " *";
+    s += "   built " + std::string(buf);
+    return s;
+}