escape special chars in filenames

This follows the escaped chars in bash completion and allows to pass
filenames with spaces etc.
Using quotes would be another option but requires special handling of
"~" and, what's worse, either hand-correcting the cursor position (into
the quoted area) or more completion mumbo-jumbo to handle the quotes.

util/fbrun/FbRun.cc

@@ -482,6 +482,13 @@ void FbRun::tabCompleteApps() {
                 std::string entry = dir.readFilename();
                 if (entry == "." || entry == "..")
                     continue;
+                // escape special characters
+                std::string needle(" !\"$&'()*,:;<=>?@[\\]^`{|}");
+                std::size_t pos = 0;
+                while ((pos = entry.find_first_of(needle, pos)) != std::string::npos) {
+                    entry.insert(pos, "\\");
+                    pos += 2;
+                }
                 if (FbTk::FileUtil::isDirectory(std::string(path + entry).c_str()))
                     m_files.push_back(prefix + entry + "/");
                 else