use the right .pub file

use the right .pub file since commit #ff14a08d changed tg.pub to tg-server.pub

telegram-cli gentoo ebuild pubkey fix

Enhance naming to show that the pubkey is the server's.

While I'm at it, also label the magic constants for prng_seed
to avoid confusion with srand(0).

Got into a situation where telegram would crash upon startup, since fetch_encrypted_message_file would end up being called with a message_media of type CODE_decrypted_message_media_document.

re-added jetbrains .idea/ and netbeans nbproject/ to gitignore