Fix handling of absolute url in kiwix-serve.

We still need to change the html content to handle absolute url in zims.

Issue has been introduced by commit 978dc47. Some code was not related
to redirection but to absolute url. I have made a clean a bit too more
aggressive.

Fix #262

src/server/kiwix-serve.cpp

@@ -806,8 +806,24 @@ static struct MHD_Response* handle_content(RequestContext* request)
     zim::Blob raw_content = entry.getBlob();
     content = string(raw_content.data(), raw_content.size());
 
+    /* Special rewrite URL in case of ZIM file use intern *asbolute* url like
+     * /A/Kiwix */
     if (mimeType.find("text/html") != string::npos) {
+      pthread_mutex_lock(&regexLock);
+      content = replaceRegex(content,
+                             "$1$2" + rootLocation + "/" + humanReadableBookId + "/$3/",
+                             "(href|src)(=[\"|\']{0,1})/([A-Z|\\-])/");
+      content = replaceRegex(content,
+                             "$1$2" + rootLocation + "/" + humanReadableBookId + "/$3/",
+                             "(@import[ ]+)([\"|\']{0,1})/([A-Z|\\-])/");
+      pthread_mutex_unlock(&regexLock);
       introduceTaskbar(content, humanReadableBookId);
+    } else if (mimeType.find("text/css") != string::npos) {
+      pthread_mutex_lock(&regexLock);
+      content = replaceRegex(content,
+                             "$1$2" + rootLocation + "/" + humanReadableBookId + "/$3/",
+                             "(url|URL)(\\([\"|\']{0,1})/([A-Z|\\-])/");
+      pthread_mutex_unlock(&regexLock);
     }
 
     bool deflated