cmd: CMD option for port number of gogs web to prevent first time run conflict

- routers: use new binding convention to simplify code
- templates: able to set HTTP port number in install page

.travis.yml

@@ -3,5 +3,11 @@ language: go
 go:
   - 1.2
   - 1.3
+  - 1.4
+  - tip
 
 sudo: false
+
+notifications:
+  email:
+    - u@gogs.io