Update ChangeLog for v1.9.4 release (#464)

ChangeLog

@@ -1,3 +1,25 @@
+v1.9.4 / 2018-01-28
+===================
+ * Fix packaging error leading to wrong version output
+ * Fix shared lib compilation (cmake -DBUILD_SHARED_LIBS=ON ..)
+
+v1.9.3 / 2018-01-28
+===================
+ * Fix compilation with "-std=c++11"
+ * Fix a gid permission issue with allow_other
+ * Fix operations on symlinks
+ * Fix a race in idle unmount
+ * Add `--reversewrite` cli option
+ * Add PID to syslog logging
+ * Deep code sanity check
+ * Modernize coding style
+ * Make codebase warnings & clang-tidy clean
+ * Bump FUSE_USE_VERSION to 29
+ * Ensure compatibility with LibreSSL
+ * Switch to vendored lib tinyxml2 & easylogging
+ * Reorganize man page and add missing options
+ * Add gtest and micro benchmarks
+
 v1.9.2 / 2017-07-25
 ===================
  * fix a use-after-free bug that was introduced in v1.9-rc1 (#214)