miscellaneous refinements

* shorten reference in note about "wmllint: recognize" magic comment to wmllint auto-recognizing characters in core macros
* comment out old orc portrait replacements instead of removing them
* switch grunt-6 replacement from warlord3 to warlord4
* soften stdout message about using frontslashes instead of backslashes in paths
* allow {NAMED_*UNIT} matches without closing brace (}), as some instances of {NAMED_UNIT} may have WML continue on another line
* make sure last field of 1.4 {LOYAL_UNIT} matches at least one non-space character
* more detailed comment on UMC data/campaigns/ -> data/add-ons/ transformation; also match additional characters [&+] in add-on folder name
* make sure there is a path= before subbing ~ in a [textdomain] or [binary_path] path
latest official version of wmllint dev branch (pre-1.11.2)
remove files on Windows so --revert and conversion can proceed (without Error 183, file already exists)

Windows won't allow a rename to overwrite an existing file.
tweak "dying words" error message to try to improve clarity

The existing error message is oblique enough that any developer who knew enough to understand what wmllint was driving at would know better than to use "die" for last words in the first place. A more direct message would be more likely to set newbie UMC authors on the right path.
miscellaneous spelling corrections
increase the number of orcish warlord portrait replacements to improve variety

With three new orc alternate portraits added during 1.9, it is no longer necessary to double-up any of the substitutions for the five old-style orcish warlord portraits.

In fact, with six portraits available, one has to draw the short straw, and I chose grunt-4. I prefer grunt-5 and grunt-6, and also find them more leaderly.
revert removal of usage class check (r48544, ai0867): caught real errors

The rationale for removing the usage class check was, "Don't make wmllint check if the usage type matches a standard one. Non-standard ones work just fine".

However, custom usage classes are relatively rare, while the check caught real errors: typos, bogus classes, using unit types instead of usage types. Other wmllint checks have higher rates of false positives.

The next commit will handle non-standard usage classes, by creating a magic comment for them.