Define Analytics works

[bobchao]

定義、開設如下目標的 Google Analytics 改進方案，然後找那些有上課的人來改：

1. 規劃全站 events category, action, label 準則
2. 歸劃、實作全站 Goals (include micro-conversions)
3. 規劃、實作重點網頁、連結的 events
   1. 首頁
   2. Firefox 產品頁
   3. Firefox for mobile 產品頁
   4. Contribute
4. 定義 Forum 的追蹤方式 <- not that easy, might need a phase II.

[bobchao]

#60 for 1
#61 for 2

#62 for 3-1
#63 for 3-2, 3-3
#64 for 3-4
(might need more if we find more issues in Step 2)

先不看 4

[bobchao]

#66 for creating a Task Force
#67 for implement / QA