Remove EnableDeleteCache

[HashidaTKS]

Which issue(s) this PR fixes:

N/A

Related: #199

What this PR does / why we need it:

In SG mode (ThinApp mode), a data folder is always removed on shutting down, so EnableDeleteCache = false doesn't work as expected, which is a specification (limitation) of ThinApp. Also, since CEF120, we should specify unique cache folder for each instances, that make re-using cache folder difficult.

Because of the reason above, we should remove EnableDeleteCache.

How to verify the fixed issue:

The steps to verify:

• Open "機能制限設定" of setting dialog
  • [x] Confirm that an option "ブラウザーキャッシュ(インターネット一時ファイル)を起動/終了時に削除する" is not exist.
  • 
• Close Chronos
  • [x] Confirm that a cache folder is remove.
  • a ceche folder is %LOCALAPPDATA%\ChronosCache\UserData for native Chronos

[kenhys]

@HashidaTKS could you resolve conflict because #199 was merged into master.

[HashidaTKS]

@HashidaTKS could you resolve conflict because #199 was merged into master.

Sure, I have resolved the conflict.