update privoxy to 3.0.24

Correct AvailabilityStatistics's behavior under special strategies like "LoadBalance", which may switch the server several times in a short period.

The executable was modified based on official release version, which
prevents privoxy from showing tray icon.
jmp dword ptr [<&SHELL32.Shell_NotifyIconA>]  => nop

This should close #455

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

add statistics config translation

ChaCha20 with an extended (96 bit) nonce and a 32-bit counter has
been implemented as crypto_stream_chacha20_ietf() from LibSodium 1.0.4

Please refer to https://tools.ietf.org/html/rfc7539 for details.

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

use __POLIPO_BIND_PORT__ to avoid potential port conflict

1. add menu items for `clear logs`, `change fonts`, `wrap text` and `top most` functions.
2. hide toolbar default. but you can trigger it out by menu.

follow with 5ae4df94e4

1. add `clean log` feature
2. add `change font` feature
3. add `wrap text` feature
4. add `top most` feature

Strategy: Simply Choose By Statistics

1. only enable menu items relevant to pac status
2. rename edit pac file into edit local pac file
3. users are allowed to enable online pac then input online pac url, not to input then enable