Fix minor whitespace and comment issues in rebar_utils
Adapt arch string to versioning scheme changes (>= 17.x)
rebar_utils:otp_release/0: handle vsn like x.y.z**

As mentioned in the OTP documentation, licensed customers may use
patched OTP installations where the otp_patch_apply tool adds a '**'
suffix as a flag saying the system consists of application versions from
multiple OTP versions. When we get such a version string, we drop the
suffix, as we cannot obtain relevant information from it as far as
tooling is concerned.
Merge pull request #327 from tuncer/fix-326

Adapt arch string to versioning scheme changes (>= 17.x)
Follow-up typo fixes for #327
Merge pull request #328 from tuncer/typos-in-327

Follow-up typo fixes for #327