Updates version number to 0.4.217718660.20181018.

Significant changes:
- Use the legacy build system.
- Removing Tulsi.xcodeproj in favor of building Tulsi with Bazel.

PiperOrigin-RevId: 217728491
diff --git a/version.bzl b/version.bzl
index a1a41f1..800a197 100644
--- a/version.bzl
+++ b/version.bzl
@@ -4,9 +4,9 @@
 # Version number (recorded into the Info.plist)
 TULSI_VERSION_MAJOR = "0"
 
-TULSI_VERSION_FIXLEVEL = "216764214"
+TULSI_VERSION_FIXLEVEL = "217718660"
 
-TULSI_VERSION_DATE = "20181011"
+TULSI_VERSION_DATE = "20181018"
 
 TULSI_VERSION_COPYRIGHT = "2015-2018"