Add Unicode tests, fix whitespace, fix docs

Added Unicode tests (and fixed few bugs), changed whitespace script to
proccess markdown files, added new guide to showcase how to work with
Unicode.

doc/Examples/Utf8Test.c

@@ -0,0 +1,66 @@
+#include <BH/IO.h>
+#include <BH/String.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+
+void printUsage(void)
+{
+    printf("Utf8Test <input> <output>\n");
+    exit(1);
+}
+
+
+int main(int argc, char **argv)
+{
+    BH_IO *inFile, *outFile;
+    char inBuffer[8], outBuffer[8];
+    uint32_t unit;
+    size_t i, inSize, outSize;
+
+    if (argc < 2)
+        printUsage();
+
+    inFile = BH_FileNew(argv[1]);
+    outFile = BH_FileNew(argv[2]);
+
+    if (!inFile || BH_IOOpen(inFile, BH_IO_READ | BH_IO_EXIST))
+        return -1;
+
+    if (!outFile || BH_IOOpen(outFile, BH_IO_WRITE | BH_IO_TRUNCATE))
+        return -1;
+
+    inSize = 0;
+    while (!(BH_IOFlags(inFile) & BH_IO_FLAG_EOF))
+    {
+        /* Read one byte and try to decode */
+        if (!inSize || !(outSize = BH_UnicodeDecodeUtf8(inBuffer, inSize, &unit)))
+        {
+            BH_IORead(inFile, inBuffer + inSize, 1, &outSize);
+            inSize += outSize;
+            continue;
+        }
+
+        /* Remove readed amount */
+        for (i = 0; i < inSize - outSize; i++)
+            inBuffer[i] = inBuffer[i + outSize];
+        inSize -= outSize;
+
+        /* Change unit if incorrect and write to output */
+        if (unit == -1)
+            unit = 0xFFFD;
+        outSize = BH_UnicodeEncodeUtf8(unit, outBuffer);
+        BH_IOWrite(outFile, outBuffer, outSize, NULL);
+    }
+
+    /* Incomplete UTF-8 sequence */
+    if (inSize)
+    {
+        outSize = BH_UnicodeEncodeUtf8(0xFFFD, outBuffer);
+        BH_IOWrite(outFile, outBuffer, outSize, NULL);
+    }
+
+    BH_IOFree(inFile);
+    BH_IOFree(outFile);
+    return 0;
+}