opened
yinyin
username_0
The following alignment styles are implemented:

- `SPACE`: vertically align with spaces. current (0.20.2) and default behavior.
- `FIXED`: just use fixed number of tabs (`CONTINUATION_INDENT_WIDTH` / `INDENT_WIDTH`).
- `VALIGN-RIGHT`: Vertically align continuation lines with indent characters. Slightly right (one more indent character) if cannot vertically align continuation lines with indent characters.

Here is how different styles look like:

<img width="274" alt="CONTINUATION_ALIGN_STYLE result sample" src="https://user-images.githubusercontent.com/71190/36948805-361ab606-201b-11e8-8c93-0d67e8f2d545.png">

with configuration:

```YAML
[style]
based_on_style = chromium
USE_TABS = true
COLUMN_LIMIT=32
INDENT_WIDTH=4
CONTINUATION_INDENT_WIDTH=8
# CONTINUATION_ALIGN_STYLE = space
# CONTINUATION_ALIGN_STYLE = fixed
# CONTINUATION_ALIGN_STYLE = valign-right
```

Comparing to previous PR:

* Renamed knob option name.
* Renamed `MORE` style to `VAlign-Right`.
* Removed `LESS` style. By discussion at #380 LESS style seems not useful.
* Added utility function `_ContinuationAlignStyleStringConverter()` to convert and check knob option string.
* More tests.
Added `CONTINUATION_ALIGN_STYLE` knob to adjust how continuation lines are vertically aligned when `USE_TABS` = True
issue