Visidata

- add options.textwrap for TextSheet
- add vd.remove(sheet)
- Sheet.sources now modifiable

- fix display/feel bugs in editText
- remove BACKSPACE for editlog undo
- fix colorizer API
- add `ctrl-u` command to toggle profiling of main thread
- fix `C`olumn statistics (`options.col_stats` still disabled by default)

- `F`requency sheet groups numeric data into intervals
- added `histogram_bins` and `histogram_even_interval` options
- added `w` command on the sheet that toggles `histogram_even_interval`
- change key for 'eval Python expression as new pyobj sheet' from Ctrl+O to Ctrl+X

- make options automatically typed based on default
- documentation cleanups
- remove R command (set filetype on CLI)

- tour of screenshot.gif
- regex transform now `*` (';' is still regex split)
- Make regex search/select to work more like vim
- Move several non-essential commands out of vd.py
- change license of vd.py to MIT
- vdtutor start
- currency type with `$`; str type moved to `~`; remove type autodetect
- www/ for landing page
- move from .md to .rst for documentation

- colorizers
- `g[` and `g]` to sort by all key columns
- `;` and `.` experimental regex commands