Rewrite the entire code-base

The following changes are focused upon:
- Modularity
- Doing away with globals
- No heap allocations
- Better command line interface
- Switch from Xlib to XCB
- More verbose type definitions
- Implement a single-file config by utilising X-macros

config.h

@@ -1,6 +1,29 @@
 #pragma once
 
-#define CLICKABLE_BLOCKS  1     // Enable clickability for blocks
-#define CMDLENGTH         45    // Trim block output to this length
-#define DELIMITER         "  "  // Delimiter string used to separate blocks
-#define LEADING_DELIMITER 0     // Whether a leading separator should be used
+// String used to delimit block outputs in the status.
+#define DELIMITER "  "
+
+// Maximum number of Unicode characters that a block can output.
+#define MAX_BLOCK_OUTPUT_LENGTH 45
+
+// Control whether blocks are clickable.
+#define CLICKABLE_BLOCKS 1
+
+// Control whether a leading delimiter should be prepended to the status.
+#define LEADING_DELIMITER 0
+
+// Control whether a trailing delimiter should be appended to the status.
+#define TRAILING_DELIMITER 0
+
+// Define blocks for the status feed as X(cmd, interval, signal).
+#define BLOCKS(X)         \
+    X("sb-mail", 600, 1)  \
+    X("sb-music", 0, 2)   \
+    X("sb-disk", 1800, 3) \
+    X("sb-memory", 10, 4) \
+    X("sb-loadavg", 5, 5) \
+    X("sb-mic", 0, 6)     \
+    X("sb-record", 0, 7)  \
+    X("sb-volume", 0, 8)  \
+    X("sb-battery", 5, 9) \
+    X("sb-date", 1, 10)