arrow

ARROW-5333: [C++] Clamp build option summary width to 90

@pitrou how does this look:

```
-- Compile and link options:
--
--   ARROW_CXXFLAGS                                                        [default=""] ""
--       Compiler flags to append when compiling Arrow
--
--   ARROW_BUILD_STATIC                                                   [default=ON] OFF
--       Build static libraries
--
--   ARROW_BUILD_SHARED                                                   [default=ON] OFF
--       Build shared libraries
--
--   ARROW_NO_DEPRECATED_API                                             [default=OFF] OFF
--       Exclude deprecated APIs from build
```

I don't *think* I touched anything but formatting, but... This is a draft because I'm getting an error:
```
CMake Error: INSTALL(EXPORT) given unknown export "arrow_targets"
```

Closes #5844 from bkietz/5333-Fit-build-option-summary- and squashes the following commits:

1045594bf <Benjamin Kietzman> ensure multiline strings are quoted when passed as parameters
0fe9fd2aa <Benjamin Kietzman> run-cmake-format.py
56b8242a9 <Benjamin Kietzman> ARROW-5333:  Clamp build option summary width to 90

Authored-by: Benjamin Kietzman <bengilgit@gmail.com>
Signed-off-by: Antoine Pitrou <antoine@python.org>