Gateoverflow

1. Now we record sessions, with `start_time` and `end_time`, which would be imortant later on for statistical reasons. For this, `recents` table is altered, `session_id` column is added.
2. Added countdown in days, with two config options `show_countdown` and `exam_date`. If enabled, it shows days remaining until `exam_date`.
3. `create` command was not implemented until now :)
4. Added aliases
- `crawl` -> `crawler`.
- `cls` -> `clear`
5. Few bugfixes, and a little bit of polishing as usual.

1. Added option to hide the title block (the logo-ish box of text in green color that appears on the top.), by setting `show_title` to either true or false.
2. Added `sample_config.toml` as `package_data`, which means, default config file is no longer read from a string constant. It's read from the `default_config.toml` file which will be included in the package.
3. Refactoring, Polished UI and Bugfixes.

1. Windows related bugfixes. It should run on windows as well, without any complaints.
2. Reverted back to `webbrowser` module because, obviously, cross-platform compatibility.

3. Fixed bugs.
4. Help message is improved.

1. fixed `latest_version_check`.

1. Added version argument, on any of the `-v`, `-version`, `--version`, shows the current version of the program.
2. Added latest version check to crawler too, cause why not!