[*]: only code-style

[*]: try to fix travis-ci build v2.1

[+]: use new version of "simple-mysqli" (4.4)

[+]: use new version of "simple-mysqli" (4.0)

[+]: use new version of "simple-mysqli" (3.0)

[+]: use new version of "portable-utf8" (3.0)

[+]: use new version of "portable-utf8" (3.0)

[+]: use new version of "simple-mysqli"

[+]: use new version of "portable-utf8" v2

[~]: fixed code-comment examples