include the channel in prefs, and don't show the updated page when in the dev channel

Makefile

@@ -97,7 +97,7 @@ all: build
 .PHONY: $(dotin_files) substitute build package publish clean
 
 substitute := perl -p -e 's/@([^@]+)@/defined $$ENV{$$1} ? $$ENV{$$1} : $$&/ge'
-export package_version update_url_tag package_url revision_id chrome_path
+export package_version update_url_tag package_url revision_id chrome_path channel
 
 $(dotin_files): $(dotin_files:=.in)
 	$(substitute) $@.in > $@

content/browser.js

@@ -83,7 +83,10 @@ let Snowl = {
       let url = "chrome://snowl/content/firstrun.html";
       setTimeout(function() { window.openUILinkIn(url, "tab") }, 500);
     }
-    else if (lastVersion != this._version) {
+    // Don't show the "updated" page in the dev channel, since we update
+    // that channel so often that this behavior would get old fast.
+    else if (lastVersion != this._version &&
+             this._prefs.get("channel") != "dev") {
       let url = "chrome://snowl/content/update.html?old=" + lastVersion +
                 "&new=" + this._version;
       setTimeout(function() { window.openUILinkIn(url, "tab") }, 500);

defaults/preferences/prefs.js.in

@@ -11,3 +11,10 @@ pref("extensions.snowl.log.appender.file.level",      "Debug");
 
 // The ID of the Mercurial revision from which a particular package is built.
 pref("extensions.snowl.revisionID", "@revision_id@");
+
+// The distribution channel for a particular package.  We use this to determine
+// whether or not to display the "updated" page when the user updates Snowl.
+// We do show the page when the user updates to a new release build; we don't
+// show it when the user upgrades to a new development build (which would get
+// old fast since they come out so often).
+pref("extensions.snowl.channel", "@channel@");