Auto register hotkeys

* Update LogForm.cs
* Update ja.txt
* Update zh_CN.txt
* Update zh_TW.txt
* Update the control name

- Naming
- Cleanup
- Move logic to controller

- Portable mode ON: executable file's folder
- Portable mode OFF: current user's temp folder

* Translation
* Environment Variables support

* Add tooltips
* Translations

Move PerPixelAlphaForm's code into QRCodeSplashForm to avoid 2 derived class of Form in same file.

Before: QRCodeSplashForm -> PerPixelAlphaForm -> Form
After: QRCodeSplashForm -> Form

Because the splash is already on the target display, the target rect doesn't need to calculate with the screen position.

"Allow Clients from LAN" --> "Allow other Devices to connect"

- update mbedtls to 2.7.0, use new md5 api
- update libsodium to 1.0.16
- static link to openssl 1.1.0g, check libsscrypto repo for detail

* Rename variable 'traffic' to 'trafficPerSecondQueue' and 'trafficInfoQueue'

* Remove class QueueLast<T> by using linq Queue.Last()

* Slight changes, such as rename, move several variables from function domain to class domain to improve performance.
Logic remains the same.

* Update the logic of copying queue from Controller to View.

* Move the TrafficInfo declaration into LogForm class

Overwise, the VS UI designer does not work.

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Don't clear the textbox, focus it instead. We want the user to see the wrong input instead of a blank textbox.

Fix #926

Use singleton mode for hotkey callbacks.

If user manually deleted servers from gui-config.json

Merge 'Switch to PAC' and 'Switch to Global'

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Also, fix typo in ProxyForm

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>

Signed-off-by: Syrone Wong <wong.syrone@gmail.com>