New search param system

 - New params "lang:" to change search language
 - New param "country:" to filter by country code
 - "time:", "gmt:" & "tzname:" params replace old "-time", "-gmt" & "-tzname" advanced searches
 - Params can be combined multiple times in a single search
 - More info: #67

Other improvements:
 - Searches are also performed on english translations of locations and zone names (#61)
 - Add some zone aliases for common places not having a timezone for them (#71)
 - New /privacy command with a link to a privacy policy on repo wiki (#66)
 - New /me command to get current user info, and updated /about (#65)
 - Update timezone database to 2018d (#74)

Under the hood changes:
 - Split sqlite framework to its own repository (#72)
 - Increase telegram query cache time to 2 seconds (#74)
 - Update telegram-bot-framework to 3.10 (#74)

New sql framework & more

- Cache recent locales on startup
- New framework for sql statements in sqlite data source

also:
- cache inline queries for 1 second
- log component migrations
- add is_bot to user

More info: #57 #58

Save left and new chat users too

Under the hood changes

- maintain a list of active chats
- add support for migrating storage sqlite components
- allow to receive results from storage calls
- make all storage operation run inside a transaction
- name storage operations
- save messages and commands to storage
- log messages on logger chat
- remove unused locks in SynchronizedCache to save memory
- Update telegram-bot-framework to 3.6.0

More info: #41 #42 #43 #44 #45 #46 #48 #49 #51 #52

General improvements

- Parametrize locales to cache on startup
- Restart time improvements and no pending commands eliminated
- Fix user_history bug in DB
- Cache locales, and improve parsing logic
- Improve user formatting
- Parametrize inline query workers

More info: #33 #34 #35 #37 #38 #39

Add preventive caching of user locale on /start command

More info: #26

Troubleshoot message & more

- new no result button that redirects to pm mode
  - displays a troubleshoot message
- new /troubleshooting command
  - displays same troubleshoot message
- some internal refactors

- Update telegram-bot-framework to 3.3.0
  - Allow to configure max_network_workers

More info: #24

Improved /start and /help commands

 - Improve /start command with switch_inline_query buttons to try some queries
 - New /help command with some links and switch_inline_query buttons with cool queries
 - Harden locale parsing to be more resilient
 - Refactor result generation to isolate from framework
 - Update to telegram-bot-framework 3.1, renaming from telegram-bot, and getting it from pypi

More info: #22 & #21

Fix error when locale does not have territory info for empty queries

More search performance improvements:

 - new locale cache framework that performs preventive and on-demand caching
 - caching es_ES and en_US locales on startup
 - /cache admin command to manage locale cache framework
 - make inline query an asynchronous action with up to 8 workers (with a min of 1 always running)
 - new SynchronizedCache to avoid generating items more than once
 - update telegram-bot to 2.6

More info: #15