Update PHP Standards.

[tfrommen]

This PR includes:

• update WPCS to v1;
• improve/fix ruleset descriptions;
• adapt ruleset to updated standards.

Also, the ruleset has been improved:

• specify current directory as default path (which can be overriden via command line);
• do not exlude *.css and *.js files, but really restrict PHPCS to PHP files only.

This PR also includes #31.

Resolves #108

[ntwb]

It'd be great to land this, without it I can't update WPCS to 1.0 locally as Composer SemVer requires HM 0.4.2 or 0.5.0 to use WPCS 0.14.0 /shrug

[mikeselander]

Might as well use 1.2.1 at this point. ignore me 😬

[joehoyle]

Do we know to what degree things have changed in 1.0.0? I don't really follow wpcs at all, but I know there's been a lot of churn, and frankly adding of pretty arbitrary "standards", so this just makes me a bit nervous. If that's all gravy, and we feel we know what we are getting ourselves in for, no worries.

[tfrommen]

@joehoyle from 0.x to 1.0.0, there did change a lot, most of it being re-structuring of rules, plus a couple deprecations here and there... In this PR, I pretty much made the resulting rules be equivalent to what we had before.

But, to be fair, this PR is almost half a year old, and WPCS is already at version 2.0.0 at the moment. Just saying...

[nathanielks]

This has been approved, can it be merged?

[joehoyle]

Do we know to what degree things have changed in 1.0.0? I don't really follow wpcs at all, but I know there's been a lot of churn, and frankly adding of pretty arbitrary "standards", so this just makes me a bit nervous. If that's all gravy, and we feel we know what we are getting ourselves in for, no worries.

[ntwb]

@joehoyle wrote:

Do we know to what degree things have changed in 1.0.0? I don't really follow wpcs at all, but I know there's been a lot of churn, and frankly adding of pretty arbitrary "standards", so this just makes me a bit nervous. If that's all gravy, and we feel we know what we are getting ourselves in for, no worries.

FWIW, WPCS 2.0.0 has since been released:

https://github.com/WordPress-Coding-Standards/WordPress-Coding-Standards/releases/tag/2.0.0

[mikeselander]

I'm going to merge this and we will be dogfooding it immediately on a client project. If any updates are needed we should know quickly and before we tag 0.6.

Note: CI isn't passing but I will fix that this week.