CRM_Utils_Check - Suggest using [cms.root], etal

[totten]

In "Admin => Resource URLs" and "Admin => Directories", sites may have a
confusing mix of absolute and relative paths, especially if they originated
in <=v4.6. This complicates migrations (e.g. moving to a new server or
syncing with a dev/staging system). In 4.7+, we can use more portable path
variables.

This is a soft suggestion (NOTICE) and not a validation error or warning.
There are obscure scenarios where one would want to use absolute addresses;
but for most sites, it's an extraneous maintenance cost.

[totten]

IMHO, the main thing that needs review is the policy & verbiage -- e.g. how best to explain this to downstream admins. Someone like @PalanteJon or @agh1 might have good insight.

[agh1]

The message in general is good, but you'll need to assure the admin that [civicrm.files] will actually resolve to the files directory they're using. Because your message will know their path and be able to resolve [civicrm.files], you could be more detailed and suggest the exact text they might want to enter. Likewise, you could check that the directory could actually be replaced safely--i.e. that [civicrm.files]/whatever would actually be the same as /whole/path/to/whatever--and issue a different message in that case.

[eileenmcnaughton]

@agh1 Can you corner @totten & get this to the point we can merge it?

[colemanw]

@totten can you please merge or close this?

[eileenmcnaughton]

I'm going to merge this - I understand the messaging could be improved & encourage anyone who would like to take a stab (@agh1) to submit a follow up PR