fix(#1030): allow cant- prefix in compound-name lint

[ext11n7]

This fixes false positives reported in #1030.

Summary:

• allow the cant- idiomatic prefix in compound-name
• document the new exception in the motive
• cover it with the existing idiomatic-prefix regression test

Note: local Maven verification was not available in this environment because mvn is not installed.

[ext11n7]

@yegor256

[volodya-lombrozo]

@rultor merge

[rultor]

@rultor merge

@volodya-lombrozo OK, I'll try to merge now. You can check the progress of the merge here.

[rultor]

@rultor merge

@volodya-lombrozo Done! FYI, the full log is here (took me 3min).

[0crat]

@volodya-lombrozo Thanks for the review! You've earned +4 points for this: +12 as a basis; -8 for absolutely no comments posted; -4 for too few (8) hits-of-code; +4 to give you at least something. Your running score is +461; don't forget to check your Zerocracy account too).

[0crat]

@ext11n7 Thanks for the contribution! You've earned +12 points for this: +16 as a basis; -4 for too few (8) hits-of-code. Please, keep them coming. Your running score is +16; don't forget to check your Zerocracy account too).