Bug 731043: add comments to confvars.sh to explain branding quirks, r=dolske

--HG--
extra : transplant_source : 7%19%93%E3%3F9%9A%F6%A6%EA%DEjB%8A%21%D43Q%F1v

browser/confvars.sh

@@ -54,8 +54,13 @@ MOZ_SERVICES_SYNC=1
 MOZ_APP_VERSION=$FIREFOX_VERSION
 MOZ_EXTENSIONS_DEFAULT=" gnomevfs"
 # MOZ_APP_DISPLAYNAME will be set by branding/configure.sh
-# Changing either of these values requires a clobber to ensure correct results,
+# Changing MOZ_*BRANDING_DIRECTORY requires a clobber to ensure correct results,
 # because branding dependencies are broken.
+# MOZ_BRANDING_DIRECTORY is the default branding directory used when none is
+# specified. It should never point to the "official" branding directory.
+# For mozilla-beta, mozilla-release, or mozilla-central repositories, use
+# "nightly" branding (until bug 659568 is fixed).
+# For the mozilla-aurora repository, use "aurora".
 MOZ_BRANDING_DIRECTORY=browser/branding/nightly
 MOZ_OFFICIAL_BRANDING_DIRECTORY=browser/branding/official
 MOZ_APP_ID={ec8030f7-c20a-464f-9b0e-13a3a9e97384}