Problem:    May get ml_get error when :pydo deletes lines or switches to
            another buffer. (Nikolai Pavlov, issue vim/vim#1421)
Solution:   Check the buffer and line every time.
https://github.com/vim/vim/commit/a58883b4ea0bbb813fd4dd7eb49dd6f03e3e5387

(We only include the tests, the Vim code changes are N/A for Nvim.)

Vim doesn't test it on Windows.
See https://github.com/vim/vim/blob/master/src/testdir/Make_all.mak

Also removes `-` before `rm -rf` as `-f` is supposed to already suppress error.

Reasoning:

- No need to check for terminal size.
- No need to mess with terminal title.
- Allows old tests to timeout with the rest of the build proceeding.
- Less and less messy output to travis log.
- Opens a path allowing old tests run in parallel. Though last bit needs test
  refactoring.

Note: code change was covered by c2a18216114bae75b6d6a2c7f1a68db04578abce

Problem:    When a multi-byte character ends in a zero byte, putting blockwise
            text puts it before the character instead of after it.
Solution:   Use int instead of char for the character under the cursor.
            (Luchr, closes vim/vim#1403)  Add a test.
https://github.com/vim/vim/commit/c81299684b2b9045e56525d3da3f45e8440fbf0d

Problem:    Still too many old style tests.
Solution:   Convert a few more tests to new style. (Yegappan Lakshmanan,
            closes vim/vim#2290)

https://github.com/vim/vim/commit/fb094e14c19337de824d4e6710ca6a2617930ab0