General enhancements

Scheme layer used: 72

This update brings a few general enhancements that are enough to deserve a new release, with a new feature: beta markdown-like parsing for .send_message()!

Additions

• .send_message() supports parse_mode='md' for Markdown! It works in a similar fashion to the official clients (defaults to double underscore/asterisk, like **this**). Please report any issues with emojies or enhancements for the parser!
• New .idle() method so your main thread can do useful job (listen for updates).
• Add missing .to_dict(), __str__ and .stringify() for TLMessage and MessageContainer.

Bug fixes

• The list of known peers could end "corrupted" and have users with access_hash=None, resulting in struct error for it not being an integer. You shouldn't encounter this issue anymore.
• The warning for "added update handler but no workers set" wasn't actually working.
• .get_input_peer was ignoring a case for InputPeerSelf.
• There used to be an exception when logging exceptions (whoops) on update handlers.
• "Downloading contacts" would produce strange output if they had semicolons (;) in their name.
• Fix some cyclic imports and installing dependencies from the git repository.
• Code generation was using f-strings, which are only supported on Python ≥3.6.

Other changes

• The auth_key generation has been moved from .connect() to .invoke(). There were some issues were .connect() failed and the auth_key was None so this will ensure to have a valid auth_key when needed, even if BrokenAuthKeyError is raised.
• Support for higher limits on .get_history() and .get_dialogs().
• Much faster integer factorization when generating the required auth_key. Thanks @delivrance for making me notice this, and for the pull request.