Updates version number to 0.4.168598667.20170913.

Significant changes:
- Adds supports for macos_unit_test and macos_ui_test.
- Cleaned up exception error messaging around aspects.

--
PiperOrigin-RevId: 168599518
MOS_MIGRATED_REVID=168599518
diff --git a/src/XcodeConfig/TulsiVersion.xcconfig b/src/XcodeConfig/TulsiVersion.xcconfig
index 48002da..ef6d134 100644
--- a/src/XcodeConfig/TulsiVersion.xcconfig
+++ b/src/XcodeConfig/TulsiVersion.xcconfig
@@ -8,8 +8,8 @@
 // Version number (recorded into the Info.plist)
 TULSI_VERSION_MAJOR = 0
 TULSI_VERSION_MINOR = $(GOOGLE_VERSION_BUILDNUMBER)
-TULSI_VERSION_FIXLEVEL = 167941708
-TULSI_VERSION_BUILDNUMBER = 20170908
+TULSI_VERSION_FIXLEVEL = 168598667
+TULSI_VERSION_BUILDNUMBER = 20170913
 
 TULSI_VERSION_COPYRIGHT = 2015-2017